To enable prevention of reading and running of a game program in an illegitimate storage medium, the disclosed slot machine includes: an SSD device including a flash memory configured to store a game program for running a game and an authentication program including an authentication key, which authenticates the game program; and a memory controller SD23 having a reference key corresponding to the authentication key, which is configured to control the storage area, and a CPU core, wherein the CPU core executes the steps of: (A) executing the authentication program in which the reference key is retrieved from the memory controller to determine whether the authentication key matches with the reference key, and if the authentication key matches with the reference key, the game program is authenticated by the authentication program; (B) starting a game by running the game program when the game program is authenticated in the step (A).