PURPOSE: To improve marking position accuracy by applying photosensitive liquid-type marking ink to both sides and dried, by laminating and exposing a specified mask film and by developing an unexposed part of photosensitive liquid-type solder resist and ink simultaneously.
CONSTITUTION: Photosensitive liquid-type marking ink 6a is applied to one side of a substrate 1 whereto photosensitive liquid-type solder resists 2a, 2b are applied and dried. Then, photosensitive liquid type marking ink 6b is applied to the other side of the substrate 1 and dried. A specified mask film 3b is laminated on both sides of the substrate 1 and positioned, and ultraviolet ray energy is irradiated and exposed. An unexposed part 4b of photosensitive liquid-type solder resists 2a, 2b and an unexposed part 4b of photosensitive liquid-type marking inks 6a, 6b are developed and removed by potassium sodium carbonate water solution simultaneously, and a specified solder resist 5 and a marking 7 are formed.