A gas treatment machine includes a main gas treatment circuit, connected to a gas compression chamber, a gas compressor, mounted in the compression chamber, a rotating electrical machine, for driving the gas compressor, including at least one coil for the flow of electric current for generating a magnetic flux, and a secondary cooling circuit, transporting gas from the compression chamber to the rotating electrical machine, for cooling this rotating electrical machine. The coil includes at least one toroidal core formed from a rolling of a plurality of turns (20) each consisting of at least one conductor (22) insulated over the length thereof by a primary insulator (24), the rolling which forms the toroidal core in turn being covered with a secondary insulator (26), the primary insulator (24) and the secondary insulator (26) including PolyEtherEtherKetone.