To provide a coin case device capable of allowing a rider to easily pay necessary coins on a bike without removing gloves.

This coin case device comprises a main body case 3 having an accommodating part for holding and accommodating coins, a main body cover 5 for opening and closing an opening part of the main body case 3 and having a hook member 4 locked on the main body case 3 to keep it in a closed state, an unlocking part 7 for unlocking a locked state of the hook member 4 of the main body cover 5 and the main body case 3, and a mounting part 9 for mounting the main body case 3 on a body.