Abstract: The invention relates to a device for compressing combustion air, in particular a device for compressing charge air for an automotive combustion engine, with at least one electrically operated charge-air compressor (12, 14), which features at least one compressor impeller (24) that is arranged in a compressor space (22) and driven by an electric motor (18), as well as with a second, additional charge-air compressor (32, 34), in particular an exhaust-gas turbocharger (34), that is connected serially to the electric charge-air compressor (14), which are connected to one another in terms of flow via connecting means (30). It is proposed in accordance with the invention that connecting means (52) are present, which make it possible to guide already compressed charge air into the compressor space (22) of the electric charge-air compressor (14).