PURPOSE: To easily assemble a compressor without composing its cylinder body and the like with divided members by forming, on the driving shaft, arm portions narrower than the width of a slider in the direction of the axis as well as a notch on a side of the slider in said direction.

CONSTITUTION: Openings 32, 33 at edges of a cylinder body 3 and a driving shaft penetrating hole 29 of a piston 6 are made in such size as to allow insertion of a slider 5, and arm portions 16a, 16b, narrower than width W of the slider 5 in the direction of an axis, are formed on the driving shaft 4, and further, a notch 37 is formed on a side of the slider 5 in the direction of the axis. This allows insertion of the piston 6 in the cylinder body 3 and installation of a crankshaft penetrating the piston 6 beforehand so that the slider 5 may be subsequently incorporated in the predetermined position from the direction of the axis of the driving shaft. Accordingly, a compressor may be easily assembled without forming the cylinder body 3, piston 6 and the like with divided members.