A method for the firing of substantially flat base ceramic articles; the method comprises: at least one conveying step, during which the base ceramic articles are conveyed along a given path, which extends from an input station to an output station through a firing chamber of a kiln; a first feeding step, during which a fuel is fed towards at least one burner; a second feeding step, during which an oxidizer is fed towards said at least one burner; a combustion step, during which a combustion mixture, which is obtained from the fuel and the oxidizer fed to said at least one burner, is burnt; at least one firing step, which is at least partially simultaneous with the combustion step and during which said at least one burner heats said firing chamber so as to fire the base ceramic articles inside the firing chamber and obtain ceramic slabs, in particular tiles; at least one first adjustment step, which is at least partially simultaneous with the combustion step and during which the flow rate of the fuel and/or of the oxidizer fed to said at least one burner during the first and/or the second feeding step is adjusted depending on a temperature detected inside the firing chamber; at least one first flow rate measuring step, during which a first flow rate measuring device estimates the flow rate of the fuel or of the oxidizer fed to said at least one burner during the first or the second feeding step; provided that when during the first adjustment step the fuel flow rate is adjusted, during the first measuring step the fuel flow rate is estimated; when during the first adjustment step the oxidiser flow rate is adjusted, during the first measuring step the oxidiser flow rate is estimated; at least one second adjustment step, during which the flow rate of the fuel and/or of the oxidizer fed to said at least one burner during the second and/or the first feeding step is adjusted depending on the flow rate of the fuel or of the oxidizer estimated during the first flow rate measuring step; and a detection step, during which the concentration of oxygen in said firing chamber is detected so as to obtain a detected concentration; during the first adjustment step and the second adjustment step, the weight ratio between the oxidiser and the fuel fed to said at least one burner is varied depending on the concentration detected; in particular, during the first adjustment step and the second adjustment step, the weight ratio between the flow rate of the oxidiser and the flow rate of the fuel fed to said at least one burner is varied so as to maintain the concentration of oxygen in the firing chamber within a third given interval. at least one conveying step, during which the base ceramic articles are conveyed along a given path, which extends from an input station to an output station through a firing chamber of a kiln; a first feeding step, during which a fuel is fed towards at least one burner; a second feeding step, during which an oxidizer is fed towards said at least one burner; a combustion step, during which a combustion mixture, which is obtained from the fuel and the oxidizer fed to said at least one burner, is burnt; at least one firing step, which is at least partially simultaneous with the combustion step and during which said at least one burner heats said firing chamber so as to fire the base ceramic articles inside the firing chamber and obtain ceramic slabs, in particular tiles; at least one first adjustment step, which is at least partially simultaneous with the combustion step and during which the flow rate of the fuel and/or of the oxidizer fed to said at least one burner during the first and/or the second feeding step is adjusted depending on a temperature detected inside the firing chamber; at least one first flow rate measuring step, during which a first flow rate measuring device estimates the flow rate of the fuel or of the oxidizer fed to said at least one burner during the first or the second feeding step; provided that when during the first adjustment step the fuel flow rate is adjusted, during the first measuring step the fuel flow rate is estimated; when during the first adjustment step the oxidiser flow rate is adjusted, during the first measuring step the oxidiser flow rate is estimated; at least one second adjustment step, during which the flow rate of the fuel and/or of the oxidizer fed to said at least one burner during the second and/or the first feeding step is adjusted depending on the flow rate of the fuel or of the oxidizer estimated during the first flow rate measuring step; and a detection step, during which the concentration of oxygen in said firing chamber is detected so as to obtain a detected concentration; during the first adjustment step and the second adjustment step, the weight ratio between the oxidiser and the fuel fed to said at least one burner is varied depending on the concentration detected; in particular, during the first adjustment step and the second adjustment step, the weight ratio between the flow rate of the oxidiser and the flow rate of the fuel fed to said at least one burner is varied so as to maintain the concentration of oxygen in the firing chamber within a third given interval.