In a horse race gaming machine 1, when a regular denomination process of S201 is executed, a regular BET image for a player to perform BET operations to a racing game is displayed on a sub monitor 113 of a station 101. In the meantime, when a high denomination process of S208 is executed, a high BET image is displayed instead of the regular BET image on the sub monitor 113 of the station 101. “2” is the minimum bet amount which can be specified in the high BET image. Alternatively, “1” is the minimum bet amount which can be specified in the regular BET image. In other words, the denomination of the high BET image is twice the denomination of the regular BET image.