Developing Device

A developing device comprising:

• a housing configured to accommodate developer therein;
• a developing roller including,
• a rotary shaft, and
• a roller main body extending in an axis line direction and having a recess portion that is recessed inwards towards a first side in the axial direction from an end surface of the roller main body, the recess portion including a side surface and a bottom surface;
• and
• a seal member arranged between the housing and the roller main body in a direction perpendicular to the axis line direction, the seal member including a first side surface at the first side in the axis line direction and a second side surface at a second side in the axial direction which is opposite to the first side,
• wherein, in the axis line direction, the bottom surface of the recess portion is positioned between the first and second side surfaces of the seal member, and
• wherein, in the axis line direction, a distance between the first side surface of the seal member and the bottom surface of the recess portion is larger than a length of a portion of the seal member that overlaps with the side surface of the recess portion in the axis line direction.