A tunnel oven for the heat treatment of friction elements as braking elements such as brake pads, comprising: a tunnel shaped protective casing extending longitudinally between its first and second open end, mutually opposing, delimiting an inlet opening and an outlet opening of the tunnel oven; a conveyor device placed within the tunnel casing and moving between the inlet opening and outlet opening, the conveyor device having a resting surface designed for receiving a plurality of friction elements to be treated to transport them between the inlet opening and the outlet opening; and at least one heating device arranged within the protective casing; wherein the heating device comprises a radiating plate made of electrically conductive material and at least one inductor arranged facing the radiating plate and spaced apart therefrom on the side opposite to the conveyor device, the at least one inductor being designed to heat the radiating plate by means of electromagnetic induction to a preset temperature; the at least one inductor being connected to a power supply of alternating electric current and to a refrigerating liquid supplier for the inductor characterized in that in combination: i)- the radiating plate made of electrically conductive material is arranged such that it faces the resting surface, at a fixed and relatively small distance from the resting surface, namely at a distance of the order of magnitude of centimeters and comprised between 1 and 19 centimeters, such distance being measured vertically from the side of the radiating plate facing towards the resting surface; ii)- the tunnel oven includes a delivery fan and/or a suction fan (21;22) hydraulically connected with at least one suction opening for ambient air, the suction opening being arranged externally to the protective casing, and hydraulically connected with a plurality of suction slots arranged within the protective casing between the resting surface and the radiating plate, along respective opposite longitudinal sides of the resting surface and of the radiating plate, in order to create within the tunnel casing and between the resting surface and the radiating plate a flow of cooling air for the braking elements; iii)- the cooling air flow is directed in counter-flow to a feeding direction of the conveyor device and also transversely to the feeding direction of the conveyor device. i)- the radiating plate made of electrically conductive material is arranged such that it faces the resting surface, at a fixed and relatively small distance from the resting surface, namely at a distance of the order of magnitude of centimeters and comprised between 1 and 19 centimeters, such distance being measured vertically from the side of the radiating plate facing towards the resting surface; ii)- the tunnel oven includes a delivery fan and/or a suction fan (21;22) hydraulically connected with at least one suction opening for ambient air, the suction opening being arranged externally to the protective casing, and hydraulically connected with a plurality of suction slots arranged within the protective casing between the resting surface and the radiating plate, along respective opposite longitudinal sides of the resting surface and of the radiating plate, in order to create within the tunnel casing and between the resting surface and the radiating plate a flow of cooling air for the braking elements; iii)- the cooling air flow is directed in counter-flow to a feeding direction of the conveyor device and also transversely to the feeding direction of the conveyor device.