To provide the communicating environment in a slot machine, particularly between a main control substrate and a sub-control substrate.

A control substrate 20 is divided into a main control substrate 200 and a sub-control substrate 300. The main control substrate 200 comprises an event order transmitting means 260 and a transmission timing varying means 270. The event order transmitting means 260 transmits the event order to the sub-control substrate 300 in one direction. The transmission timing varying means 270 varies the transmission timing of the event order at random within a specific time range. The sub-control substrate 300 comprises an event order receiving means 310 and a sub-display control means 330.