PURPOSE: To achieve a prevention of occupation of more than one pachinko machine at the same time effective by a method where holding time is counted when the place ment of an object other than pachinko balls on a tray is detected with a tray sensor of a pachinko on machine while no pachinko game is played at the pachinko machine and a play forbidding signal is outputted after the holding time expires.

CONSTITUTION: An upper tray 3 of the pachinko machine 1 is provided with two tray sensors 5 and 6 comprising respective light emitting elements and photo detectors 7, 8 and 9, 10 to detect the placement of an object other than pachinko balls on the upper tray 3 and when an output signal is provided from any one of the tray sensors 5 and 6, an H signal is outputted from a sensor circuit 12. A touch circuit 14 is provided to detect whether and operation handle 2 is held by a player or not and a detection signal thereof is checked upon with the output signal of the sensor circuit 12 by means of an AND gate 13 and when the outputs of the circuits 12 and 14 are all the H signals, a timer circuit 15 is started. When the timer circuit 15 counts a specified holding time, a forbidding signal is outputted from a latch circuit 18 to forbid pachinko playing.