Abstract: A fluid machine for compressing or conveying fluids, in particular for compressing gases to high pressures, has a linear motor (2), at least one cylinder (3), a solid or liquid piston (4, 4?) which can be moved axially in the cylinder (3), and at least one compression space (5) which is formed between the cylinder (3) and the solid or liquid piston (4, 4?), wherein the linear motor (2) applies translational driving force to the solid or liquid piston (4, 4?). For such a fluid machine, the leakage-free and lubricant-free compression and conveying of fluids, in particular a compression of gases to high pressures, and a rather simple construction is made possible owing to the fact that the solid or liquid piston (4, 4?) is surrounded in the area of the linear motor (2) by a firmly attached pipe section (6).