A control valve is configured such that a suction pressure, which is used to displace a sub-valve element in a valve opening direction after a main valve has been closed, is varied according to a value of current supplied to a solenoid. A crankcase communication port, which communicates with a crankcase of a compressor, and a suction chamber communication port, which communicates with a suction chamber of the compressor, are provided in a body. A sub-valve chamber whose diameter is larger than that of the main valve hole is formed between the crankcase communication port and a main valve hole, and a sub-valve is placed in the sub-valve chamber.