PURPOSE: To prevent the generation of painting inferiority while reducing the replacement frequency of a filter, by bringing paint mist into contact with recirculation water of the filter apparatus, the filter of a filter apparatus and an electric dust collector in succession in this order.

CONSTITUTION: Paint mist is brought into contact with recirculation water H of a wet filter apparatus 27 along with air conditioning air supplied to a painting booth to perform primary mist removal and said air is subsequently and continuously passed through the filter 38 of the regenerable filter apparatus 27 to perform secondary mist removal while third mist removal is further performed by an electric dust collector 26. By this method, the generation of painting inferiority such as color mixing or blistering is prevented and the replacement frequency of the filter is reduced.