In a developing assembly comprising a developer-carrying member and a developer quantity control blade kept in pressure contact with the developer-carrying member, the developer-carrying member has a deformation percentage D of 0.5% or less in the direction of pressure contact, and the developer quantity control blade has a ten-point average roughness Rz of from 0.3 m to 20 m at its surface on the side kept in contact with the developer-carrying member (a charge control face). The developing assembly can prevent faulty images such as lines and uneven images due to the deformation of developer-carrying member even though any deformation due to the pressure contact of the developer quantity control blade has taken place in the developer-carrying member while the developing assembly is stopped.