In a control valve for a variable capacity compressor, coolant that is sucked in from a suction chamber through a suction conduit is compressed and delivered to a delivery chamber through a delivery conduit and the coolant pressure is controlled by an electromagnetic control valve. Opening/closing control of a gas supply valve body (gas supply side) that communicates with the delivery conduit and a crank chamber and of an extraction valve body (extraction side) that communicates with the crank chamber and the suction conduit is performed in accordance with the suction coolant pressure of the suction conduit. A crank chamber communication port communicates with the extraction valve chamber.