PURPOSE: To enable to readily break the seal of a semiconductor device by covering a semiconductor chip with a protection cover having a hole, and dropping resin dissolving medicine through the hole, thereby breaking the seal.

CONSTITUTION: A medicine resistant protection cover 15 which has a circular or polygonal more than square of the size equal to a semiconductor chip 11 in a diameter of a center around e point crossing an extension line d vertically extended from the front surface of the chip 1 from the crossing point c of the diagonal liens a, b of the chip 1 with the surface of resin 12 to cover all or the corresponding part of the surface or the like corresponding to the surface of the chip 11 of the entire semiconductor device except the hole, is used to break the seal of the semiconductor device while dropping dissolving medicine 13 through the cover to the device.