A control valve according to one embodiment includes a shaft that transmits the solenoidal force to a valve element. The control valve also provides for stable operation of a variable displacement compressor even under high-temperature and high-pressure environments. A solenoid includes a bottomed sleeve into which the pressure of refrigerant is introduced, a core secured coaxially to the sleeve, a plunger, contained in the sleeve on its bottom side, which is displaceable integrally with the shaft in a direction of axis line, a first spring that applies the biasing force in a valve opening direction to the shaft, a second spring that applies the biasing force in a valve closing direction to the plunger, and a shaft support member, which is press-fitted such that the shaft support member is secured to an inner wall of the sleeve near its bottom portion. The second spring is set between the shaft support member and the plunger.