To provide an epoxy resin composition having excellent crack resistance.

The epoxy resin composition is composed of an epoxy resin mixture containing an epoxy resin, a hardener and a catalyst and a filler. The filler is produced by adding metal powder containing ≥70% particles having particle diameters of 10-50μm to an electrically insulating filler powder containing ≥70% particles having particle diameters of 10-50μm and having a thermal conductivity of ≥5 W/(m×K) at 25°C to obtain the sum of volume fractions of the filler powder and the metal powder of 30-60% and the volume fraction of the metal powder of ≤20%. At least one substance selected from alumina, boron nitride, aluminum nitride, aluminum borate, crystalline silica and zirconium can be used as the filler powder and copper or iron can be used as the metal powder.