To provide a control board storing case for a game machine which can not be opened without leaving a trace and can be sealed again.

The control board storing case 1 is sealed by fastening a pair of boss parts 16a-16d and flange parts 17a-17d using a fastening screw 21 provided with an operating head part 22 which can be operated to screw only in the fastening direction, and the control board storing case is not opened without destroying a sealed part. Only on the boss parts 16b-16d except the boss part 16a used for the first fastening, entrances 24 through which spare screws 21' for fastening screws 21 required for re-sealing can be taken in and out, is provided. Storing parts 25 whose entrances 24 are blocked by the flange parts 17a-17d when sealing is performed, are respectively provided.