Developing device

A developing device comprising:

• a rotatable developer bearing member configured to bear developer on a surface;
• a regulation member configured to regulate a thickness of the developer borne on the surface of the developer bearing member, an end of the regulation member in a direction orthogonal to a rotation axis direction being in contact with the surface of the developer bearing member;
• a frame configured to support the developer bearing member, the other end of the regulation member in the orthogonal direction being fixed to the frame, the frame including a recess in an opposed surface opposed to the regulation member, the recess being recessed in a direction away from the regulation member and extending from a center portion toward both end portions in the rotation axis direction, a width, in the orthogonal direction, of the recess at both the end portions increasing gradually as distance from the center portion in the rotation axis direction increases;
• and
• a sealing member provided in the recess to seal a gap between the regulation member and the frame, the sealing member being formed by ejecting thermally melted resin into the recess.