The method of the invention is used for monitoring the state of a smoke duct connecting each suction rail of a baking furnace (FAC) for carbonated blocks, of the rotating fire type and preferably with open chambers or covered chambers, to a smoke processing center (CTF) for purifying the baking smoke from the FAC, wherein said smoke is drawn through at least one suction rail of the FAC and collected in the smoke duct feeding said smoke to the CTF, the method including at least the step of detecting a leak in the smoke duct consisting of parasitic inlets of ambient air into said duct and/or at least the step of detecting a fire in said duct.