The invention relates to a heat exchanger, particularly for a motor vehicle, comprising a first component with a first duct, a second component with a second duct and a thermoelectric element for generating a heat flow, wherein a first fluid of a first fluid circuit can be caused to flow through the first duct to control the temperature of a first external component, wherein a second fluid of a second fluid circuit can be caused to flow through the second duct, which is fluidically separated from the first duct, to control the temperature of a second external component, and wherein the at least one thermoelectric element is arranged between the first and second components, contacting same thermally.