In a compressor that changes a discharge capacity by using an actuator, a variable displacement swash plate type compressor capable of realizing reduction in manufacture cost is provided. In the compressor of the present invention, a ring groove is formed in a movable body, and the ring groove is provided with an annular member. The annular member has a joint gap formed by a first to a third cutouts, and the third cutout is an aperture. In this compressor, the annular member moves in the ring groove based on a pressure difference between a control pressure chamber and a swash plate chamber. Thereby, in the compressor, a pressure in the control pressure chamber is regulated by regulating a flow of a refrigerant that flows to the swash plate chamber from the control pressure chamber.

There is provided a valve capable of reducing valve leakage. The valve includes: a valve housing in which ports through which a fluid passes are formed; a valve body configured to be driven by a drive source; a valve seat on which a contact portion of the valve body is seated; and biasing members for biasing the valve body in a valve closing direction. The valve seat is formed of an elastic member.