The present invention provides a resin composition including: (A) a silicone resin containing a constitutional unit shown by the following composition formula (1) and having a weight average molecular weight of 3,000 to 500,000; (B) an epoxy resin-curing agent; and (C) a filler; wherein the mass fraction of the component (C) is 50 to 95% by mass based on the total mass. This can provide a resin composition that can mold a wafer in a lump, has good molding properties particularly to a thin-film wafer having a large diameter, gives low-warping properties, as well as good wafer protection properties, high reliability, and good heat resistance after molding, can perform a molding process favorably, and can be used for wafer level packaging favorably.