To attain simplification of air piping, fluid pressure piping, device total unit, eliminate a mounting bracket, improve mounting workability in a vehicle, and attain reduction of a cost.

Relating to a pressure chamber 11 of a power cylinder 10, a switching valve MGV switching supply/discharge of compressed air, control valve 21, stroke cylinder 13 adjacent to the power cylinder 10 are provided, a double check valve DCV is interposed between the switching valve, control valve and the pressure chamber 11, compressed air can be supplied to the pressure chamber 11 selectively via either one of the switching valve or control valve, the control valve 21 and the stroke cylinder 13 are arranged in the same side relating to the power cylinder 10, and the control valve 21 and the double check valve DCV are integrally arranged in a cylinder main unit 35 of the stroke cylinder 13.