The invention relates to a device to compress combustion air, in particular a device to compress combustion air for a combustion engine of a motor vehicle, with a housing (12), with at least one compressor impeller (30) arranged in a compression area (28) of a first housing part (14), which is arranged in the flow direction between an air inlet (24) and an air outlet (43) of the housing (12), as well as with an electric motor (18) arranged in a second housing part (16) of the housing (12) to operate the compressor impeller (30). It is proposed in accordance with the invention that a flow channel (42) running in the circumferential direction of the first housing part (12) and connecting the compression space (28) with the air outlet (43) surrounds the electric motor (18) at least partially.