A heat exchanger (1) includes a fluid collector (2) for receiving fluid, a multiphase distributor (3) for distributing fluid, a first flow path (4), and a plurality of multi-duct tubes (6), which each have a duct tube longitudinal axis (7) and which each lead into the multiphase distributor (3) and into the fluid collector (2) by forming an orifice (8, 9). A second flow path (5) leads respectively through the multi-duct tubes (6), the fluid collector (2), and the multiphase distributor (3), wherein the multi-duct tubes (6) extend through the first flow path (4) for the first fluid, so that the first fluid can flow around and the second fluid can flow through the multi-duct tubes (6).