Abstract: A multi-stage compressor for compressing a fluid, the compressor comprising two or more cylinders each having a compression chamber and a piston, so that a fluid in each of the compression chambers can be com-pressed by the associated piston; the cylinders being connected in series such that a fluid entering an inlet of the compressor can be compressed to a first pressure in the compression chamber of a first cylinder and, then, enter into the compression chamber of a second cylinder where the compressed fluid is compressed to a second higher pressure and, before the fluid exits from an outlet of the com-pressor; wherein each piston is driven by one and the same crankpin of the compressor. Furthermore, a method for compressing a fluid, and a system for comprising the multi-stage stage compressor are disclosed.