Abstract: Regenerator with tube system, particularly for fireplaces and the like, which can be inserted at the firebox of fireplaces and comprises a metallic heat-exchange body that is constituted by a single tubular body shaped so as to have straight and parallel portions that rest on the heart of the firebox, two identical curved loop portions that rest on the rear vertical wall of the firebox, a single transverse loop lying at the front of the firebox, and two ends that are parallel and close to each other, and are directed towards the outside of the fireplace, one of the ends being connected to a box-like body that contains a motorized fan for sending the ambient air to be heated into the heat-exchange body, the other end being connected to a duct for delivering the heated air into the surrounding space, the delivery duct being also contained in the box-like body.