To provide a rapid cooling method of a channel induction heating device capable of efficiently performing rapid cooling in a short time without using a special device, and without damaging a used refractory.

In this rapid cooling method of the used channel induction heating device 11 having a maximum inner width of a runner 10 of 6-30 cm, dry ice including powder mainly composed of substances having maximum lengths of 3-30 mm and unavoidably mixed therein, is filled in the runner 10, and the air is supplied to the runner 10 filled with the dry ice at a flow rate of 0 or 0 to 1.2 Nm3/hour.