A machine for making liquid/semi-liquid food products includes a container for the product； a dispenser connected to the container which allows or inhibits dispensing of the product； a mixing stirrer rotatable about an axis of rotation and mounted inside the container； a thermal system including a circuit with a heat exchanger fluid and an evaporator operatively associated with the container and including an inlet aperture for the fluid, a discharge aperture for the fluid, a first tubular element and a second tubular element coaxial with the first tubular element and having an axial direction of extension and a radial direction of extension, the second tubular element extending along an axial direction parallel to the axis of rotation and being disposed inside the first tubular element to define an annular chamber for circulating the fluid and defined by at least one microchannel, the microchannel having a hydraulic diameter of 3-13 mm.
