PURPOSE: To enhance the close adhesiveness between paints, in forming two layers or more of paint films to an article to be painted, by gradually increasing and decreasing the spray amounts of paints by allowing the same to correlate to each other.

CONSTITUTION: At first, a paint A is sprayed onto an article 1 to be painted, to which electrodeposition painting was applied preliminarily, to form a paint film 2 only comprising the paint A. Next, the spray amount of a paint B is gradually increased simultaneously while the spray amount of the paint A is gradually decreased to form a mixed paint film 3 of both paints A, B. Then, the paint B is sprayed to form a paint film 4 only comprising the paint B and these films are baked. In this paint film constitution, the close adhesiveness between both paint films is enhanced as compared with such a case that the kinds of two paints are almost perfectly changed at the interface of two paint films.