diff --git a/.gitignore b/.gitignore
index 74ee902..d896434 100644
--- a/.gitignore
+++ b/.gitignore
@@ -33,3 +33,6 @@ __pycache__/
 *.cif
 *.rcif
 *.ort
+
+# User configuration
+config.*.json
diff --git a/resources/config.sample.json b/resources/config.sample.json
index 57f2aae..aec802d 100644
--- a/resources/config.sample.json
+++ b/resources/config.sample.json
@@ -31,12 +31,13 @@
     "config_file" : "config.json",
     "verbose" : false,
     "file_log" : false,
-    "file_log_base_name" : ".scicat_ingestor_log",
+    "log_file_suffix" : ".scicat_ingestor_log",
     "file_log_timestamp" : false,
-    "debug_level" : "INFO",
+    "log_level" : "INFO",
     "system_log" : false,
     "system_log_facility" : "mail",
     "log_prefix" : " SFI: ",
-    "check_by_job_id" : true
+    "check_by_job_id" : true,
+    "pyscicat": null
   }
 }
diff --git a/src/scicat_configuration.py b/src/scicat_configuration.py
new file mode 100644
index 0000000..958798b
--- /dev/null
+++ b/src/scicat_configuration.py
@@ -0,0 +1,143 @@
+# SPDX-License-Identifier: BSD-3-Clause
+# Copyright (c) 2024 ScicatProject contributors (https://github.com/ScicatProject)
+import argparse
+from dataclasses import dataclass
+from typing import Mapping, Optional
+
+
+def build_main_arg_parser() -> argparse.ArgumentParser:
+    parser = argparse.ArgumentParser()
+
+    group = parser.add_argument_group('Scicat Ingestor Options')
+
+    group.add_argument(
+        '-c',
+        '--cf',
+        '--config',
+        '--config-file',
+        default='config.20240405.json',
+        dest='config_file',
+        help='Configuration file name. Default: config.20240405.json',
+        type=str,
+    )
+    group.add_argument(
+        '-v',
+        '--verbose',
+        dest='verbose',
+        help='Provide logging on stdout',
+        action='store_true',
+        default=False,
+    )
+    group.add_argument(
+        '--file-log',
+        dest='file_log',
+        help='Provide logging on file',
+        action='store_true',
+        default=False,
+    )
+    group.add_argument(
+        '--log-file-suffix',
+        dest='log_file_suffix',
+        help='Suffix of the log file name',
+        default='.scicat_ingestor_log',
+    )
+    group.add_argument(
+        '--file-log-timestamp',
+        dest='file_log_timestamp',
+        help='Provide logging on the system log',
+        action='store_true',
+        default=False,
+    )
+    group.add_argument(
+        '--system-log',
+        dest='system_log',
+        help='Provide logging on the system log',
+        action='store_true',
+        default=False,
+    )
+    group.add_argument(
+        '--system-log-facility',
+        dest='system_log_facility',
+        help='Facility for system log',
+        default='mail',
+    )
+    group.add_argument(
+        '--log-prefix',
+        dest='log_prefix',
+        help='Prefix for log messages',
+        default=' SFI: ',
+    )
+    group.add_argument(
+        '--log-level', dest='log_level', help='Logging level', default='INFO', type=str
+    )
+    group.add_argument(
+        '--check-by-job-id',
+        dest='check_by_job_id',
+        help='Check the status of a job by job_id',
+        action='store_true',
+        default=True,
+    )
+    group.add_argument(
+        '--pyscicat',
+        dest='pyscicat',
+        help='Location where a specific version of pyscicat is available',
+        default=None,
+        type=str,
+    )
+    return parser
+
+
+@dataclass
+class RunOptions:
+    config_file: str
+    verbose: bool
+    file_log: bool
+    log_file_suffix: str
+    file_log_timestamp: bool
+    system_log: bool
+    system_log_facility: str
+    log_prefix: str
+    log_level: str
+    check_by_job_id: bool
+    pyscicat: Optional[str] = None
+
+
+@dataclass
+class ScicatConfig:
+    original_dict: Mapping
+    """Original configuration dictionary in the json file."""
+    run_options: RunOptions
+    """Merged configuration dictionary with command line arguments."""
+
+
+def build_scicat_config(input_args: argparse.Namespace) -> ScicatConfig:
+    """Merge configuration from the configuration file and input arguments."""
+    import copy
+    import json
+    import pathlib
+    from types import MappingProxyType
+
+    # Read configuration file
+    if (
+        input_args.config_file
+        and (config_file_path := pathlib.Path(input_args.config_file)).is_file()
+    ):
+        config_dict = json.loads(config_file_path.read_text())
+    else:
+        config_dict = dict()
+
+    # Overwrite deep-copied options with command line arguments
+    run_option_dict: dict = copy.deepcopy(config_dict.setdefault('options', dict()))
+    for arg_name, arg_value in vars(input_args).items():
+        if arg_value is not None:
+            run_option_dict[arg_name] = arg_value
+
+    # Protect original configuration by making it read-only
+    for key, value in config_dict.items():
+        config_dict[key] = MappingProxyType(value)
+
+    # Wrap configuration in a dataclass
+    return ScicatConfig(
+        original_dict=MappingProxyType(config_dict),
+        run_options=RunOptions(**run_option_dict),
+    )
diff --git a/src/scicat_ingestor.py b/src/scicat_ingestor.py
index 13aa104..b07e2a8 100644
--- a/src/scicat_ingestor.py
+++ b/src/scicat_ingestor.py
@@ -1,7 +1,11 @@
 # SPDX-License-Identifier: BSD-3-Clause
 # Copyright (c) 2024 ScicatProject contributors (https://github.com/ScicatProject)
+from scicat_configuration import build_main_arg_parser, build_scicat_config
 
 
 def main() -> None:
     """Main entry point of the app."""
-    ...
+    arg_parser = build_main_arg_parser()
+    arg_namespace = arg_parser.parse_args()
+    config = build_scicat_config(arg_namespace)
+    print(config)
diff --git a/tests/test_scicat_configuration.py b/tests/test_scicat_configuration.py
new file mode 100644
index 0000000..85dbd5b
--- /dev/null
+++ b/tests/test_scicat_configuration.py
@@ -0,0 +1,80 @@
+# SPDX-License-Identifier: BSD-3-Clause
+# Copyright (c) 2024 ScicatProject contributors (https://github.com/ScicatProject)
+import argparse
+
+import pytest
+
+from scicat_configuration import ScicatConfig
+
+
+@pytest.fixture
+def main_arg_parser() -> argparse.ArgumentParser:
+    """Return the namespace of the main argument parser."""
+    from scicat_configuration import build_main_arg_parser
+
+    return build_main_arg_parser()
+
+
+def test_scicat_arg_parser_configuration_matches(
+    main_arg_parser: argparse.ArgumentParser,
+) -> None:
+    """Test if options in the configuration file matches the argument parser."""
+    import json
+    import pathlib
+
+    scicat_namespace = main_arg_parser.parse_args(
+        ['-c', 'resources/config.sample.json']
+    )
+
+    # Check if the configuration file is the same
+    assert scicat_namespace.config_file == 'resources/config.sample.json'
+    config_path = pathlib.Path(scicat_namespace.config_file)
+    config_from_args: dict = vars(scicat_namespace)
+
+    # Parse the configuration file
+    assert config_path.exists()
+    config_from_file: dict = json.loads(config_path.read_text())
+    main_options: dict = config_from_file.get('options', dict())
+
+    # Check if all keys matches
+    all_keys = set(config_from_args.keys()).union(main_options.keys())
+    for key in all_keys:
+        assert key in config_from_args
+        assert key in main_options
+
+
+def test_build_scicat_config_default(main_arg_parser: argparse.ArgumentParser) -> None:
+    """Test if the configuration can be built from default arguments."""
+    from scicat_configuration import build_scicat_config
+
+    scicat_namespace = main_arg_parser.parse_args()
+    scicat_config = build_scicat_config(scicat_namespace)
+    assert scicat_config.original_dict['options']['config_file'] == 'config.json'
+    assert scicat_config.run_options.config_file == 'config.20240405.json'
+
+
+@pytest.fixture
+def scicat_config(main_arg_parser: argparse.ArgumentParser) -> ScicatConfig:
+    from scicat_configuration import build_scicat_config
+
+    scicat_namespace = main_arg_parser.parse_args(
+        ['-c', 'resources/config.sample.json', '--verbose']
+    )
+    return build_scicat_config(scicat_namespace)
+
+
+def test_build_scicat_config(scicat_config: ScicatConfig) -> None:
+    """Test if the configuration can be built from arguments."""
+    assert scicat_config.original_dict['options']['config_file'] == 'config.json'
+    assert scicat_config.run_options.config_file == 'resources/config.sample.json'
+    assert not scicat_config.original_dict['options']['verbose']
+    assert scicat_config.run_options.verbose
+
+
+def test_scicat_config_original_dict_read_only(scicat_config: ScicatConfig) -> None:
+    """Test if the original dictionary is read-only."""
+    from types import MappingProxyType
+
+    assert isinstance(scicat_config.original_dict, MappingProxyType)
+    for sub_option in scicat_config.original_dict.values():
+        assert isinstance(sub_option, MappingProxyType)