PURPOSE: To downsize an electric apparatus and also, cut down the manufacture cost by screwing the male screw at one end of a pillar-shaped screw into the female screw part of the housing of an electric apparatus so as to fix an electric circuit board 2, and screwing a screw into the female screw part at the other end of the pillar-shaped screw.

CONSTITUTION: An electric circuit board 2 is arranged in the specified position where the housing of an electric apparatus is to be fixed, and the electric circuit board 2 is fixed to the housing 3 of the electric apparatus by screwing the male screw 6' at one end of a pillar-shaped screw having screw parts at both ends into the female screw part 4' of the housing of an electric apparatus. An insulating protective cover 1 is placed in the specified position of the fixed electric circuit board 2, and is fixed by screwing a screw 4 into the female screw part 6" at the other end of the pillar-shaped screw 6. As a result, the electric circuit board 2 covered with the insulating protective cover 2 is accommodated and fixed in the housing 3 of the electric apparatus. Accordingly, the electric apparatus can be downsized, and the manufacture cost can be cut down.