Disclosed is a swash plate type variable displacement pump. The pump comprises a spring which biases a swash plate in a direction of decreasing the tilting angle thereof, a hydraulic cylinder which controls the swash plate at the tilt angle according to a load on the pump by the resisting force against the biasing force of the spring, a valve allows a pressurized fluid to flow into the hydraulic cylinder when opened, and prevents the pressurized fluid from coming out of the hydraulic cylinder when closed, and a fluid discharge passage which gradually releases the resisting force of the hydraulic cylinder against the spring to slowly shift the tilt angle of the swash plate to 0.degree..