Widths of a coating area, a developing agent carrier, a maximum image area and a first cleaning member taken along a second direction are respectively W1, W2, W3 and W4, the following conditions are satisfied:a first condition that W1>W2 is met and in the second direction, the both edges of the developing agent carrier are located on the inner side to the both edges of the coating area,a second condition that W2>W3 is met and in the second direction, the both edges of the image area are located on the inner side to the both edges of the developing agent carrier, anda third condition that W4>W2 is met and in the second direction, the both edges of the developing agent carrier are located on the inner side to the both edges of the first cleaning member.