To provide a board case by which a dishonest act can be completely prevented, and the desired aim can be achieved, by unremovably engaging locking pieces of a cover body with locking holes of a base plate.

In a board case comprising a base plate 11 to be mounted on a game machine 1, a circuit board 12 mounted on a front face of the base plate 11, and a synthetic resin box-shaped cover body 13 mounted on the base plate 11 in such manner that it covers the circuit board 1, a slide plate 20 slidable in the vertical direction, is mounted on the front face of the base plate 11, the projecting pieces 21, 21 positioned at a specific interval from the front face of the base plate 11, are mounted on the both sides of the slide plate 20, the locking holes 25, 25 are formed on the front faces of the projecting pieces 21, 21, and the first locking pieces 30, 30 engaged with the locking holes 25, 25, and linked by the link part for disengagement, and the second locking pieces 31, 31 which can be engaged with the engaging holes 25, 25 when the first locking pieces are disengaged from the link part for disengagement, and the slide plate 20 is slid, are integrally formed on the both sides of the cover body 13.