Abstract: A heater, especially a motor vehicle heater which can be operated independently of the engine, with a burner which is supplied with fuel and air via a binary nozzle (2), a combustion chamber (1), and a multistage compressor (3, 4) for compressing the air. The entire mass flow of air necessary for combustion in the combustion chamber (1) is sent to at least one first compressor stage (3) for compression to a first pressure level, and the air mass flow compressed in this way is divided into a first component flow supplied directly to the combustion chamber (1), and a second component flow which is compressed in at least one second compressor stage (4) to a second pressure level and sent to the binary nozzle (2) as the fuel atomization air mass flow.