Telephone having phone number registration function, phone number registration method, and call register display method

A telephone that includes: a storage unit ; a transmission/reception unit for, when an incoming call is received, acquiring a caller's phone number corresponding to the incoming call; a counting unit for measuring a time period between a start of a reception of the incoming call and a disconnection of the incoming call; and a one-ring-call judgment unit for, if the measured time period is shorter than a predetermined time period, instructing a general control unit to store the acquired phone number into the storage unit as a target for a connection rejection so that if an incoming call is received from a caller having the stored phone number thereafter, a connection thereto is rejected.