A charge amount controlling roller serving as a charge amount controlling member is placed to face to a developing roller and is disposed on an upstream side, in a rotation direction of the developing roller, of a developing position at which a photosensitive drum and the developing roller face to each other. The charge amount controlling roller is biased with a voltage having the same polarity as that of non-latent-image portions on the photosensitive drum with respect to the developing roller, thereby reducing extraordinarily charged developing agents, or high charged, low charged, reverse charged toners otherwise causing image defects such as fogs.