PURPOSE: To realize the longer stroke by simultaneously moving a second member in the longitudinal direction of a cylinder body oppositely to the moving direction of a piston and a first member, by the motion of the piston in response to the application of the fluid pressure.

CONSTITUTION: A second slider (second member) 16 is mounted on a tubular body 1 at a side opposite to a first slider (first member) yoke 8 side. The second member 16 has the shape similar to that of the yoke 8, and longitudinally movable along the tubular body 1 similarly as the yoke 8. Two belts 24 having the function as a flexible driving means are disposed on two rollers 20, and the ends of these belts 24 are connected by the yoke 8 and the second member 16. By alternately supplying the compressed air to two cylinder chambers, the piston 6 is moved forward and backward, and the yoke 8 and the second member 16 are linearly moved along the tubular body 1 at the same speed in the opposite direction.