To obtain a B-stage sheet suitable for a high-specific-permittivity capacitor and to obtain a high-density printed circuit board prepared by using the same.

A resin composition essentially comprising 100 pts.wt. epoxy resin which is liquid at room temperature and 0.01-20 pts.wt. thermal curing catalyst is compounded with an insulating inorganic filler having a specific permittivity at room temperature of 500 or higher in an amount of 80-99 wt.%. The resultant composition is used for preparing a high-specific-permittivity B-stage sheet, which is used for preparing a high-density printed circuit board. Thus, a high-specific-permittivity printed circuit board excellent in heat resistance, electrical properties after moisture absorption, adhesion to a copper foil, etc., can be prepared.