To provide a game medium cleaning system capable of retaining a game medium sanitary.

This game medium cleaning system uses detergent prepared by mixing surfactant with acid electrolytic water having high sterilizing property or alkaline electrolytic water having high decomposition power to organic substances such as protein, and forming them into cationic or anionic surfactant and has improved sterilizing property and detergency. The detergent is liquid to be coveringly stuck to the whole body of the game medium, has the high sterilizing property and detergency, sufficiently cleans the whole body of the game medium, and retains the game medium sanitary.