Method for inspecting porous plate surface and apparatus for inspecting porous plate surface

The purpose of the present invention is to provide a method and an apparatus for inspecting a porous plate surface, which are capable of accurately detecting dirt, scratches, plating failure, adhesion of foreign substances and the like on the surface of a porous plate. According to the present invention, an image of a surface (Wa) of a porous plate (W) is taken by an imaging unit (4), while irradiating the porous plate (W) with illuminating light for reflection from the front surface side of the porous plate (W) and also irradiating the porous plate (W) with illuminating light for backlight from the back surface side of the porous plate (W). Then, the quantity of reflected light (12) reflected by the surface (Wa) of the porous plate (W) and the quantity of transmitted light (11) transmitted through a through hole portion (Wc) of the porous plate (W) are determined on the basis of the image, and the quantity of the illuminating light for reflection and the quantity of the illuminating light for backlight are a