A photo-curable resist resin composition for electroless plating comprising an epoxy resin having a viscosity of at least 150 poises at 25.degree. C., and at least two glycidyl ether groups in one molecule, the glycidyl ether groups being directly bonded to the aromatic ring as Component A, an oxirane ring-containing compound having a boiling point of at least 140.degree. C. and a molecular weight of not more than 500 as Component B, and a photo-sensitive aromatic onium salt as Component C, wherein the Component A is in an amount of 90 to 40 parts by weight per total 100 parts by weight of the Components A and B, and the Component C is in an amount of 0.1 to 5 parts by weight per total 100 parts by weight of the Components A and B, and, if any, other resin components, can produce a resist film capable of withstanding highly alkaline electroless copper plating solution at a high temperature for a long time without any decrease in the physical properties of plating films deposited even by repeated use of the electroless copper plating solution. The resist film prepared from the resist resin composition has distinguished soldering heat resistance, solvent resistance and electrical insulation.