Exhaust gas turbocharger for a combustion engine

The turbocharger has a compressor (12) which comprises a compressor wheel (14) arranged with a diffuser in a compressor housing (30). A turbine (10) comprises a turbine wheel in a turbine housing (18). A bearing housing (24) is provided, in which a shaft is mounted. The shaft connects the compressor wheel with the turbine wheel. A rear wall of the diffuser is cooled with cooling agent. The rear wall is directed to the bearing housing. A closed annular cooling agent channel is formed on the rear wall. The cooling agent channel extends around the entire circumference of the diffuser.