The invention relates to a device and a method for control of the operation of a thermal projection torch (12), characterized in that the characteristics of the jet (16) and the temperature of the deposit (24) on the piece (22) are measured by means of a camera (54) and a combined pyrometer (70). The correction to be made to the supply parameters of the torch (12) are deduced therefrom and the corrected parameters are transmitted to the unit (30) controlling the torch (12).