To end the big bonus under the optimum conditions without exciting gambling spirits of players in vain.

When a player sets the number of bets by casting tokens or operating a BET button as the game keeps a big bonus mode, the value of a number of acquired token counter is subtracted by the number of bets set only (S301). The end of each round of game and the putting out of the tokens enable the value of the number of acquired token counter to be added by the number of tokens put out (S321). When the value of the number of acquired token counter exceeds 300, that is, when a player acquires the number of tokens exceeding 300 after the start of the big bonus mode (S322), the big bonus game flag is cleared (S325) to end the big bonus game mode. The big bonus game mode is also ended when the counts of the regular bonus game based on the number of minor combination games and the JACIN reach a prescribed value (S323 and S324).