A kiln for firing ceramic slabs (T) comprising: a heating module , a firing module , a cooling module , consecutively connected to each other along an advancement direction (Y) of the slabs (L), which define a process chamber (C) provided with an inlet opening (A) and an outlet opening (B); a transport system (T1,T2) arranged along the process chamber (C) from the inlet opening to the outlet opening, structured to transport the slabs (L) along the advancement direction (Y); wherein the process chamber (C) comprises at least a first channel (C1) and at least a second channel (C2), thermally isolated from one another, each of which extends along the advancement direction (Y) from the inlet opening (A) to the outlet opening (B); wherein the transport system (T1,T2) comprises at least a first transport line (T1) and at least a second transport line (T2), respectively arranged along the first channel (C1) and along the second channel (C2) from the inlet opening (A) to the outlet opening (B); characterised in that: the heating module and/or the cooling module comprise a plurality of sub-modules , flanked to one another along the slab advancement direction (Y); each sub-module is separated from the adjacent sub-modules by means of insulating partitions, provided with openings, aligned with each other along the advancement direction, to allow the transit of the slabs (L), and wherein each sub-module is provided with temperature adjusting means independent of the other sub-modules . a heating module , a firing module , a cooling module , consecutively connected to each other along an advancement direction (Y) of the slabs (L), which define a process chamber (C) provided with an inlet opening (A) and an outlet opening (B); a transport system (T1,T2) arranged along the process chamber (C) from the inlet opening to the outlet opening, structured to transport the slabs (L) along the advancement direction (Y); wherein the process chamber (C) comprises at least a first channel (C1) and at least a second channel (C2), thermally isolated from one another, each of which extends along the advancement direction (Y) from the inlet opening (A) to the outlet opening (B); wherein the transport system (T1,T2) comprises at least a first transport line (T1) and at least a second transport line (T2), respectively arranged along the first channel (C1) and along the second channel (C2) from the inlet opening (A) to the outlet opening (B); characterised in that: the heating module and/or the cooling module comprise a plurality of sub-modules , flanked to one another along the slab advancement direction (Y); each sub-module is separated from the adjacent sub-modules by means of insulating partitions, provided with openings, aligned with each other along the advancement direction, to allow the transit of the slabs (L), and wherein each sub-module is provided with temperature adjusting means independent of the other sub-modules . the heating module and/or the cooling module comprise a plurality of sub-modules , flanked to one another along the slab advancement direction (Y); each sub-module is separated from the adjacent sub-modules by means of insulating partitions, provided with openings, aligned with each other along the advancement direction, to allow the transit of the slabs (L), and wherein each sub-module is provided with temperature adjusting means independent of the other sub-modules . <EOS>