PROBLEM TO BE SOLVED: To provide a suction button equipped with a plunger having a valve part with a large diameter and capable of being easily incorporated in a cylinder.SOLUTION: A straight pipeline 41 and a valve receiving part 42 are provided at a valve guide member 24 and a pair of pawl parts 52 are provided at a first tip part 50a of a valve mechanism part 25a while a conical valve part 51 is provided at a first rear end part 50b of the valve mechanism part 25a. The head 55 is provided at a second tip part 54a of a pressure operation part 25b and a pawl locking hole 56 is provided in a second rear end part 54b. A pair of the pawl parts 52 of the valve mechanism part 25a are inserted into the straight pipeline 41 from a rear end cylinder opening 46 and locked with the pawl locking hole 56 of the pressure operation part 25b positioned on the side of a leading end side cylinder opening 35 to connect the valve mechanism part 25a to the pressure operation part 25b. A connection plunger 25 is incorporated in the valve guide member 24 in a state that the conical valve part 51 is not passed through the pipeline of the valve receiving part 42.
