Abstract: The invention relates to a heat exchanger for a mobile heating device comprising a burner, the heat exchanger having a carrier body with an inner face and an outer face. The inner face of the carrier body is formed as an inner exhaust gas duct for conducting exhaust gas of the burner. Furthermore, a channeling is arranged between the inner face and the outer face of the carrier body for conducting a heat transfer medium. The heat transfer medium is in heat conducting contact, via the inner face, with exhaust gas in the inner exhaust gas duct. At the outer face of the carrier body, an outer exhaust gas duct for conducting exhaust gas of the burner is provided. The heat transfer medium is in heat conducting contact via the outer face of the carrier body with exhaust gas flowing in the outer exhaust gas duct. The present invention further relates to a mobile heating device having a burner and to such a heat exchanger and to a motor vehicle comprising such a heating device.