Nitriding equipment for oriented electromagnetic steel plates and nitriding method

Equipment that continuously nitrides strips that continuously passing through a production line for oriented electromagnetic steel plates, after cold rolling and before secondary recrystallization annealing. The equipment comprises a nitriding zone in which strips are nitrided, a cooling zone in which the strips are cooled, and a heating zone in which strips are heated prior to the nitriding zone if necessary. An electrode for glow discharging is arranged in the nitriding zone. Plasma nitriding by glow discharging is performed on the strip being used as a negative electrode, using this electrode for glow discharging as a positive electrode. As a result, inhibitor-forming elements are dispersed across the entire length and the entire width of the strip, and an oriented electromagnetic steel plate having excellent magnetic properties with no variation is obtained thereby.