A variable displacement compressor control valve, for varying a discharge capacity of the compressor, said compressor compressing a refrigerant led into a suction chamber and discharging the compressed refrigerant from a discharge chamber, characterized in that a part of the discharged refrigerant being introduced into a control chamber via a supply passage while part of refrigerant in the control chamber being released to the suction chamber via a release passage, so that pressure in the control chamber is regulated in such a manner that a discharging capacity of the compressor is regulated, the control valve controlling the discharging capacity by regulating a flow rate of refrigerant flowing through the supply passage, the control valve comprising: a body having a discharge chamber communication port communicating with the discharge chamber, a control chamber communication port communicating with the control chamber, and a suction chamber communication port communicating with the suction chamber, an internal passage connecting the discharge chamber communication port and the control chamber communication port constituting the supply passage, the body having a valve hole provided in the internal passage; a valve element for adjusting an opening degree of a valve section by moving toward and away from the valve hole, the valve element receiving a differential pressure (Pd - Ps) between a discharge pressure (Pd) of the discharge chamber and a suction pressure (Ps) of the suction chamber in a valve opening direction; and a solenoid, provided in the body, which generates a solenoidal force with which to drive the valve element in a valve closing direction according to an amount of current supplied thereto, wherein the valve element autonomously operates so that the differential pressure (Pd - Ps) between the discharge pressure (Pd) and the suction pressure (Ps) is kept at a preset differential pressure according to a value of current supplied to the solenoid, wherein the control valve further has a bleed hole which is provided in the body separately from the valve hole, and which has a leak passage with a diameter which is smaller than a diameter of the valve hole, and permits refrigerant to be leaked from the discharge chamber communication port to the control chamber communication port even while the valve section is closed, and wherein the bleed hole is formed such that the following expression is satisfied, where X represents the diameter of the leak passage and Y represents a diameter of the release passage: Y > 2.145X + 0.24. a body having a discharge chamber communication port communicating with the discharge chamber, a control chamber communication port communicating with the control chamber, and a suction chamber communication port communicating with the suction chamber, an internal passage connecting the discharge chamber communication port and the control chamber communication port constituting the supply passage, the body having a valve hole provided in the internal passage; a valve element for adjusting an opening degree of a valve section by moving toward and away from the valve hole, the valve element receiving a differential pressure (Pd - Ps) between a discharge pressure (Pd) of the discharge chamber and a suction pressure (Ps) of the suction chamber in a valve opening direction; and a solenoid, provided in the body, which generates a solenoidal force with which to drive the valve element in a valve closing direction according to an amount of current supplied thereto, wherein the valve element autonomously operates so that the differential pressure (Pd - Ps) between the discharge pressure (Pd) and the suction pressure (Ps) is kept at a preset differential pressure according to a value of current supplied to the solenoid, wherein the control valve further has a bleed hole which is provided in the body separately from the valve hole, and which has a leak passage with a diameter which is smaller than a diameter of the valve hole, and permits refrigerant to be leaked from the discharge chamber communication port to the control chamber communication port even while the valve section is closed, and wherein the bleed hole is formed such that the following expression is satisfied, where X represents the diameter of the leak passage and Y represents a diameter of the release passage: Y > 2.145X + 0.24.