The compressor of the invention comprises: a block with a cylinder; a movable assembly formed by a piston reciprocating in the cylinder and coupled to an actuating means by a rod; and a resonant spring having a first and a second diametrical end portion which are attached to the movable assembly by a first fixation means (MF1) and, to the block, by a second fixation means (MF2) which is adjustably attached to the block and to said second end portion so as to affix the latter to the block in a position defined along the displacement of the resonant spring in three directions orthogonal to one another and defined by the direction of the axis of the resonant spring, by the diametrical direction of the second end portion and by the diametrical direction orthogonal to said two first directions, and also along the angular displacement of said second end portion around said three directions orthogonal to each other.