A connector device comprises a connector and a mating connector. The connector comprises a housing and a slider having a second regulated portion. The mating connector comprises a mating housing having a second regulation portion. The connector is movable between an open position and a closed position. The slider is held by the housing to be movable between a first position and a second position. When the connector is moved to a predetermined position together with the slider which is located at the second position upon a movement of the connector from the closed position toward the open position, the second regulated portion is brought into abutment with the second regulation portion, and a movement of the connector toward the open position beyond the predetermined position is regulated. When the slider is moved to the first position, the connector is movable to the open position.