An image forming apparatus includes a placement tray, an image forming unit, a drive unit, a control board, a power supply substrate, a high-voltage board, and low-voltage power supply harnesses. The placement tray holds a recording sheet thereon. The image forming unit forms an image on the recording sheet. The drive unit supplies driving force to the image forming unit. The control board controls the drive unit. The power supply substrate supplies electric power to the control board. The high-voltage board is disposed in one side of the placement tray. In the high-voltage board, voltage is generated higher than voltage in the power supply substrate. The low-voltage power supply harnesses are disposed in another side of the placement tray so as to supply electric power from the power supply substrate to the control board.