PURPOSE: To provide excellent reliability as compared with a conventional plastic sealing material by using coarse filler and fine filler.

CONSTITUTION: An improper phenomenon is mostly caused in a sealed IC having an aluminum circuit 1 and a protective film 2 due to the influence of a large filler, by the abnormal circuit such as water introduction occurred in a microcrack 4 of a boundary between a resin bulk and a resin, water introduced occurred by a damage by a crack 5 a circuit protective film and displacement 5 or a deformation of the aluminum circuit. In other words, the present filler has larger particle diameter than the circuit width, the particle size distribution is wide, and large irregularity in the filling particle diameter with irregular local stress occurs. Then, rough filler (having twice or more of the circuit width of semiconductor to be sealed with powder diameter and less than 100microns) and fine filler (smaller than the width of a semiconductor circuit to be sealed with powder diameter) are used together, thereby remarkably reducing the impropriety.