To provide a compact prizing device of a Pachinko machine which can detect game balls accurately and never generate excessive prize winning.

An obstacle 51b is formed in a left-side rail wall 51 which constitutes an ordinary electromotive accessory actuation prize gate 22 of a Pachinko machine, and a fall preventing section 52b in the shape of a curved surface extended diagonally to the upper left is formed in a right-side rail wall 52. When a game ball enters the ordinary electromotive accessory actuation prize gate 22, the ball abuts against the obstacle 51b and reduces its falling speed, allowing the accurate detection of the ball. Since the ball is guided in the inclination direction of the fall preventing section 52b when the ball abuts against the fall preventing section 52b, excessive prize winning of balls can be suppressed. Since the obstacles 51b and the fall preventing sections 52b for detecting the game ball accurately and suppressing the excessive prize winning of game balls are installed to the right and left sides of the prizing device, no projection of the device toward the player is required, thus making the device compact.