The resin composition, a resin sheet, a resin sheet with a metal foil, a cured resin sheet structure, and a power source or a semiconductor device

The resin composition of the present invention contains an epoxy resin comprising a polyfunctional epoxy resin, a phenol novolak resin curing agent comprising a structural unit represented by the following general formula (the I), and an inorganic filler comprising a nitride particles. In the general formula (I), R1 and R2 each independently represent a hydrogen atom or a methyl group, m represents an average value of 1.5 to 2.5, n represents an average value of 1 to 15.