The game apparatus is provided with the cylindrical portion rotating with the axis on the side face of the base portion of the master control lever. Two projecting parts are sticking out from the columnar surface of the cylindrical portion. In addition, two leaf switches are provided corresponding to the master control lever. The leaf switch is turned on when the projecting part contacts with the contact member of the leaf switch while the master control lever is rotating. In this way, operation of the master control lever is detected by using the leaf switches rather than rotary switches.