A half fitting prevention connector includes a cylindrical case, a connector body, a lever, and a release lever. The release lever has a lock hole. An electromagnetic coil has a plunger. The plunger is arranged so as to face a microswitch. The electromagnetic coil is excited by connection between the signal terminal of the connector body and a signal terminal of a mating connector, and thereby moving the plunger toward the microswitch. The release lever is rotatable so that the plunger can enter the lock hole to press the microswitch in a state that the connector body is completely fitted with the mating connector and the plunger cannot enter the lock hole in a state that the connector body is half fitted with the mating connector.