A connector device comprising a connector and a mating connector connectable with each other, wherein: the mating connector comprises a mating housing, a mating primary terminal and a mating secondary terminal; the mating primary terminal and the mating secondary terminal are held by the mating housing; the connector comprises a housing, a primary terminal, a secondary terminal and an operation member; the primary terminal is held by the housing; the operation member is attached to the housing; a movement of a part or whole of the operation member relative to the housing causes a state of the operation member to be changed from an initial state to a first state, and another movement of a part or whole of the operation member relative to the housing causes the state of the operation member to be changed from the first state to a second state; when the operation member is in the initial state, the primary terminal is unconnected to the mating primary terminal, and the secondary terminal is unconnected to the mating secondary terminal; when the state of the operation member is changed from the initial state to the first state, the primary terminal is moved relative to the mating primary terminal to be connected to the mating primary terminal; and when the state of the operation member is changed from the first state to the second state, the secondary terminal is moved relative to the mating secondary terminal to be connected to the mating secondary terminal; characterized in that the connector comprises a push-back mechanism and when the state of the operation member is changed to the first state, the push-back mechanism applies a push-back force to the operation member, wherein the push-back force pushes back the operation member to change the state of the operation member back toward the initial state. the mating connector comprises a mating housing, a mating primary terminal and a mating secondary terminal; the mating primary terminal and the mating secondary terminal are held by the mating housing; the connector comprises a housing, a primary terminal, a secondary terminal and an operation member; the primary terminal is held by the housing; the operation member is attached to the housing; a movement of a part or whole of the operation member relative to the housing causes a state of the operation member to be changed from an initial state to a first state, and another movement of a part or whole of the operation member relative to the housing causes the state of the operation member to be changed from the first state to a second state; when the operation member is in the initial state, the primary terminal is unconnected to the mating primary terminal, and the secondary terminal is unconnected to the mating secondary terminal; when the state of the operation member is changed from the initial state to the first state, the primary terminal is moved relative to the mating primary terminal to be connected to the mating primary terminal; and when the state of the operation member is changed from the first state to the second state, the secondary terminal is moved relative to the mating secondary terminal to be connected to the mating secondary terminal; characterized in that the connector comprises a push-back mechanism and when the state of the operation member is changed to the first state, the push-back mechanism applies a push-back force to the operation member, wherein the push-back force pushes back the operation member to change the state of the operation member back toward the initial state.