To provide a method for forming a resist which enables protection of a BTH(blind through-hole) portion of a substrate from an etching solution, and which is simple, less costly, and not affected by the land width of the BTH.

In a method for forming a resist layer, using a liquid resist onto a substrate having a blind through-hole portion, the liquid resist is applied onto the substrate by electrostatic atomization painting and then dried in such a manner that the thickness of the resist layer in the through-hole portion is not less than 1/5 of the depth of the blind through-hole and a dry thickness becomes not less than 15μm, and that the resist applied by painting has a viscosity of 50-5000 poises at 25°C and has a solid component of 50-90wt.%.