To provide a releasability-imparting resin composition which is used e.g. for smoothly releasing a molded item from a metal mold which has been stained by the repetition of molding operation using a thermosetting resin composition for molding semiconductor devices.

This releasability-imparting resin composition is prepared by using a masterbatch prepared by mixing an epoxy resin or a phenol resin with at least a part of a mold release agent to be used. The composition contains 0.6-7 wt.% release agent. Preferably, the release agent content of the masterbatch is set at 1-20 wt.%. Preferably, the composition is used in a sheet form.