To provide an epoxy resin composition for semiconductor sealing, exhibiting excellent markability with a YAG laser in spite of containing no electroconductive colorant such as carbon black.

This composition is an epoxy resin composition essentially consisting of an epoxy resin, a phenolic resin, an inorganic filler, a cure accelerator, and an organic dye having an absorption spectrum at 800-1,200 nm, wherein the inorganic filler is present in an amount of 65-92 wt.% based on the entire composition, and the organic dye is present in an amount of 0.05-3 wt.% based thereon.