PURPOSE: To prepare a plating material excellent in heat resistance simply and inexpensively within a short time, by applying rapid heating treatment to a plating surface formed on a substrate metal and comprising a different kind of a metal diffusible with said substrate metal by a heating roll.

CONSTITUTION: On a substrate metal such as a copper type material, a different kind of a metal such as silver diffusible with said substrate metal is plated in a plating process 1, according to necessity, through a diffusion barrier wall such as a nickel plating layer and the plating layer is rapidly heated by a heating roll to carry out heat treatment to wind up the heat treated plated metal by a winder 4. The heating roll 3 has a resistance wire mounted therein while a current is supplied to said resistance wire through a carbon brush and the plating surface of the plated strip 2 is heated to a temp. corresponding to a line speed for a short time of about 10sec or less. The above mentioned heat treatment can be carried out in the atmosphere and can be performed in either one of a continuous process or a separate process after the plating process 1.