To provide a photo-thermally curable resin composition which can easily fill holes such as through-holes, does not sag, and can be easily photo- cured; and a hole-filled printed circuit board which does not allow dents, cracks, etc., to occur on cured resin parts, is excellent in solder resistance, does not cause the corrosion of metal parts, and can produce a high-reliability long-life electric appliance free from short circuit, defective electrical connection, etc.

This resin composition contains (I) an unsaturated fatty acid partial adduct of an epoxy resin, (II) a (meth)acrylate, (III) a photo-crosslinker, (IV) a liquid epoxy resin, and (V) a latent curing agent.