Substantial difficulties related to collecting data/metadata from EEG/ERP experiments are presented. Because of suitable ontology describing EEG/ERP experiments does not exist authors present a custom ontology that is proposed to be discussed within the scientific community. The presented ontology is practically implemented within the EEG/ERP Portal. The EEG/ERP Portal simultaneously serves to interested community as a tool for sharing and managing of custom EEG/ERP experiments. Because of domain ontologies are expressed by the Semantic Web languages (OWL) authors' present briefly introduction into the Semantic Web technologies. Because of the Semantic Web languages expressivity is different in contrast with the object-oriented code, that is the most often used in current software development, authors' present the developed Semantic Framework. This framework ensures adding a missing semantic into the input object-oriented code and its transformation into appropriate OWL constructs. Integration of the Semantic Framework into the EEG/ERP Portal ensures an online serialization of stored experiments into an OWL document. A registration of the developed ontology in NIF validates authors' approach. The NIF registration also enables easy sharing of stored experiments.