PURPOSE: To adapt a compressor for a compact size by specifying its construction.

CONSTITUTION: An electromotive compressor 10 is constructed by setting an electric motor 10a to a compressor 10b in which the first compressing chamber 25 in a piston crank part 24 and the second compressing chamber 26 in a piston cylinder part 20 are respectively formed and the first suction valve 28 in a protection cover 27 of the crank part 24 and the second suction valve 29 in a piston 21 are respectively provided. In this construction, the piston 21 is reciprocated vertically by the electric motor 10a to introduce air into the first compressing chamber 25 through the first suction valve 28, and after the compressed air is supplied to an air shock absorber 14 from the second compressing chamber 26 through a discharge valve 32, the compressed air in the first compressing chamber 25 is introduced into the second compressing chamber 26 through the second suction valve 29. Consequently, since the compressed air discharged from the discharge valve 32 is compressed both in the first and the second compressing chamber 25 and 26, the whole system can be adapted for a compact size by the promotion of the compressing efficiency on the basis of the compressor 10b.