A valve housing has a communication passage communicating a suction port of the compressor with a crank chamber of the compressor. A valve element opens and closes the communication passage, and a spring member resiliently biases the valve element toward the closed position. A pressure actuated unit moves the valve element toward the open position by a suction pressure of the compressor. The spring member includes a spring made of a temperature responsive material. The spring decreases in its resilient force in an opening direction of the valve element with increase of an outer-air temperature. The spring member has a primary spring made of an ordinary resilient material for resiliently biasing the valve element toward the closed position and a correction spring made of a material having a temperature positive characteristic. The correction spring provides a correction spring force smaller than a primary force of the primary spring in the opposite direction to the primary force. The combined spring force of the primary spring and the correction spring acting on the valve element.