PURPOSE: To rapidly and exactly heat a strip to a prescribed temp. at the time of gas wiping and/or alloying treatment in continuous hot dip metal coating.

CONSTITUTION: The strip S is immersed continuously into a molten metal bath 2 and is plated. The strip is directly energized by using the molten metal bath 2 and at least a pair of touch rolls 6, 8 installed upper than gas wiping nozzles 5 as electrodes, by which the strip is heated. The adjustment of the coating weight of plating and the acceleration of the alloying treatment of the plating layer are facilitated. This method is excellent in responsiveness to a change in the kinds of products, etc.