As conventional methods for forming a coating on a surface of a member, for example, a dipping method, a spray method, and an electrodeposition coating method are known. For example, Japanese Patent Application Publication No. JP 09-262519 A discloses a technology in which a coating is formed on only a predetermined portion by performing electrodeposition coating after masking the other portion by using UV cured resin.
When coating is performed by the dipping method or the spray method, it is difficult to form a coating having a uniform thickness on side surfaces of a platy member, and portions of a first surface and a second surface (a surface on the side opposite to the first surface) of the platy member, which are close to end portion of the platy member. In contrast to this, the thickness of a coating is likely to be made uniform when coating is performed by the electrodeposition coating method. However, it is difficult to form a coating on only a part of a member. Therefore, a portion on which coating is not performed is masked in advance, and the mask is removed after a coating is formed. These steps make the production process complicated.