To provide a circuit board case in which a history is left when a pin is forcedly removed, by using the pin having a structure to be hardly pulled out.

The circuit board case 1 for housing circuit boards for games built into game machines such as slot machines is provided with a board case body 3 carrying the main board, a board case lid part 2 covering the board case body 3, a board base 5 for fixing the the circuit board case 1 on the enclosure of the game machine, a caulked pin 6 piercing the board case body 3, the board case lid part 2 and the board base 5 to fix integrally. The caulk pin 6 has a tip part 6a capable of being broken when a pulling-out of the pin 6 is tried and a head part 6b which presses the board case lid part 2. A notch 6c is formed at the center of the tip part 6a of the caulk pin 6 and formed into a wedge toward the tip thereof. The caulk pin 6 is preferably made of a synthetic resin.