PURPOSE: To prohibit an increase in the sound pressure of noise with an adjacent structure and to prevent large noise in ambient environment by shielding the spacing between a static induction electric apparatus and the adjacent structure by using a part of the walls of a structure commonly as a part of a soundproof body for housing the static induction electric apparatus or covering the space between this soundproof body for housing the static induction electric apparatus and the adjacent building.

CONSTITUTION: The space between the transformer reactor 1 and a building 2 for housing a thyristor valve is shielded by opening the wall on the side where the building 2 for housing the thyristor valve and the transformer reactor 1 are connected and by using a part of the wall of the building 2 for housing the thyristor valve as a part of the soundproof body 3 for housing the transformer reactor. As a result, the initial cost of the soundproof body 3 for housing the transformer reactor is reduced by as much as the common use. The soundproof, body 3 for housing the transformer reactor may be formed of the same material (for example, concrete) as the material of the building 2 for housing the thyristor valve or may be a tank made of steel plates.