A machine for making liquid or semi-liquid food products includes: a first processing container for processing a liquid or semi-liquid base product and defining a processing chamber; a stirrer for mixing the product in the first processing container; a thermal system including a heat exchanger, associated with the first processing container, wherein the heat exchanger includes a hollow element extending along an axis and provided externally with grooves defining a path extending along the axis and at least one duct disposed inside the grooves.