A displacement control mechanism used in a variable displacement compressor for controlling a displacement of the compressor includes a first control valve located on a supply passage and a second control valve located on a first bleed passage. The second control valve includes a backpressure chamber having substantially the same pressure atmosphere as a region of the supply passage downstream of the first control valve and a spool including a back surface that is located in the backpressure chamber. The spool reduces an opening degree of the first bleed passage when a pressure in the backpressure chamber is increased. The spool blocks a communication between the backpressure chamber and the first bleed passage via a clearance formed around a cylindrical outer peripheral surface of the spool in the second control valve when the spool sets the first bleed passage at a minimum opening degree.