A slider is displaceable in an axial direction on guide sections of a cylinder tube. Bearings are installed with the slider, so that the bearings are opposed to the guide sections. Bearings are also installed on first and second bearing support members, which are provided respectively at retaining sections of the slider. When the slider is displaced in the axial direction along the cylinder tube, only one end surface of one of the flange sections of the bearing is pressed, depending on the displacement direction of the slider, in order to effect displacement in an integrated manner.