To provide a rotary drum type game machine using game balls, capable of detecting shortage of game balls in advance.

Take-in devices 301-303 have take-in parts (composed of a take-in gate member, a guide and a solenoid) for taking in game balls, and a standby ball number detection sensor 803 for detecting standby balls waiting on the upstream side of the take-in parts, so that the number of standby game balls waiting on the upstream side of the take-in parts can be detected. More specifically, the number of standby game balls to be taken in the next time in the take-in devices 301-303 can be detected, and therefore, the shortage of game balls can be detected in advance. Furthermore, the detected number of standby game balls can be utilized for the advance notice of the shortage of game balls.