A plate-tube type heat exchanger not requiring maintenance is described, comprising: a plate with a plurality of channels running parallel along thereof; and, a plurality of tubes housed and secured to said channels, thus forming a circuit for the circulation of a heating fluid, a cooling fluid or a means of heating; the plate includes integrally attachment means associated to each channel, which in their closed position, cover along with its corresponding channel, almost the entire tube external perimeter housing in said channel, thereby securing each of the tubes to the whole plate, without the use of welding and a large contact surface is achieved for the heat conduction between the plate and each one of the tubes.