Heat exchanger and method for manufacturing same

The device (1) has an outer housing (2) and an inner housing (3) with multiple housing portions assembled such that a U-shaped fluid channel (6) is formed in the inner housing and a cooling passage is formed between the inner housing and the outer housing. Heat-conducting ribs extend from a cooling passage surface (5) into the fluid channel, where the cooling passage surface and the heat-conducting ribs are integrally formed in a hollow body. The cooling passage surface acts as a cover element for the inner housing. An independent claim is also included for a method for manufacturing a heat exchanger device.