In a system having an interface that utilizes an electroencephalogram, there is realized a calibration which prevents overlooking of calibrational stimulations concerning the electroencephalogram and which is highly accurate.An electroencephalogram interface system (1) includes an interface section (100) which acquires an electroencephalogram signal from a user, distinguishes a P3 component of a visual event-related potential contained in the electroencephalogram signal after a manipulation menu is presented, and operates a device based on the distinguished P3 component. An electroencephalogram distinction method adjustment apparatus (10) is used for adjusting a distinction method in the interface section (100). Based on a database (13) defining a correlation between a P3 component of an event-related potential obtained from a stimulation to a modality other than the visual sense and a P3 component of a visual event-related potential and on a P3 component of an event-related potential after a stimulation is presented, the apparatus (10) derives a characteristic quantity of the user concerning the P3 component of the visual event-related potential, and adjusts the electroencephalogram distinction method in the interface section (100) based on the characteristic quantity.
