The invention relates to a device for controlling and/or regulating an annealing or heat treatment furnace (2) of a production line (1) processing metal material, which comprises the annealing or heat treatment furnace (2) and at least one measuring instrument (7, 8, 17), which detects at least one material property of a strip material (6) located in the production line (1), wherein the annealing or heat treatment furnace (2) and the at least one measuring instrument (7, 8) interact in a regulating and/or control circuit of an automated process control, which regulates and/or controls the annealing or heat treatment furnace (2) in connection with a furnace control, wherein according to the invention, a solution is created wherein an improvement of the process control over the previously known prior art can be achieved. This is achieved in that the at least one measuring instrument (7, 8) is arranged behind the annealing or heat treatment furnace (2) in the strap material processing direction (5) and detects online a measured value reproducing and/or depicting a mechanical material property of the strap material (6) and transmits said measured value to a regulating and/or control unit (18) as a data transfer signal.