An avionics module including an electronic circuit board, a case in which the circuit board is positioned and including at least one inlet orifice and at least one outlet orifice for cooling air, a first corridor for the circulation of the cooling air formed between a first face of the circuit board and a first facing wall of the case, and a second corridor for the circulation of the cooling air formed between a second face of the circuit board and a second facing wall of the case. The module includes at least one baffle for controlling the distribution of the cooling air between the first and second corridors. Preferably, the baffle is fixed to the electronic circuit board.