IMAGE FORMING APPARATUS

PROBLEM TO BE SOLVED: To detect accurately that collected waste toner has reached a predetermined amount.SOLUTION: An image forming apparatus 1 includes a photoreceptor 41, a transfer part 45, a transfer belt 48, a photoreceptor cleaning part 47, a transfer belt cleaning part 49, a toner container 7, a light transmission part 71, an optical sensor 8, and an application voltage adjustment part 109. The photoreceptor cleaning part 47 and the transfer belt cleaning part 49 remove toner from the photoreceptor 41 and the transfer belt 48. The toner container 7 houses waste toner. The light transmission part 71 is provided in the toner container 7. The optical sensor 8 detects a state of the toner container 7 by transmitting light through the light transmission part 71. The application voltage adjustment part 109 applies a voltage to a screw shaft 97 provided in a waste toner conveyance path 9 for conveying waste toner to the toner container 7, to apply a voltage to the waste toner. The waste toner is charged with a predetermined polarity and potential.