To prevent a fraudulent act caused by an operation of an inside of a game machine.

A game system has a game machine 1 and a game media management device 2 which is connected to the game machine 1 so that it can transmit/receive a variety of data and signals to/from the game machine 1. The game media management device 2 has a bet processing part. The bet processing part transmits to the game media management device 2 a token charge request signal of the number of bets or the number of chargeable tokens designated by a bet number designation part when the bet number designation part is operated, when a token charge request reception state signals that is not 0 before execution of a game starts is received, and does not transmit the token charge request signal to the game media management device 2 when the bet number designation part is operated, when the token charge request reception state signal that is not 0 is received during execution of the game.