PURPOSE: To provide a method for forming electrodeposition coating films contg. an antimicrobial agent having sufficient sterilizing potency, where films retains the color tones, gloss and surface condition of a material be coated as they are, have excellent durability and are safe to the human body, by codepositing the antimicrobial agent which does not cause the elution of antimicrobial metal ions, the discoloration by a change with lapse of time, the degradation in antimicrobial potency, etc., on the electrodeposition coating film surface.

CONSTITUTION: The antimicrobial agent consisting of ceramic particulates of calcium phosphate securely deposited with metal silver having the antimicrobial property is dispersed into an electrodeposition coating soln. 6 and ornaments, etc., 3 are subjected to electrodeposition coating and simultaneously, the antimicrobial agent is codeposited on their surfaces, by which the electrodeposition coating films contg. the antimicrobial agent are formed.