To improve responsiveness of a valve by surely deaerating in pilot pressure oil in the pilot operation type valve, operated by the pilot pressure to be introduced in a pilot chamber.

A bleeder throttle passage 19, which is to be connected to a tank return oil passage 16, is formed in the upper part of an upper side pilot chamber 8A for introducing the pilot pressure oil and a thermal expansion member 18 or enlarging the area of the opening of the throttle passage, according to the temperature of the pilot pressure oil, is disposed in the throttle passage.