A collation processing apparatus includes user identification information memory means for storing user identification information which identifies a user, collation information input means for inputting collation information, collating means for carrying out collation processing on the basis of the collation information input by the collation information input means, user identification information reading means for reading out predetermined user identification information from the user identification information memory means on the basis of a collation result by the collating means, and output means for outputting, to external equipment, user identification information which has been read out by the user identification information reading means, thereby making it possible to specify a user. By setting a communication address serving as user identification information in the external equipment by address setting means, data communication in which the user is specified can be carried out.