A developer supply device is provided, which includes a developer retrieving member disposed to face a developer holding surface of a developer holding member across a predetermined distance in a position downstream relative to a developer supply position where the developer holding member faces an intended device to be supplied with development agent in a direction perpendicular to a main scanning direction parallel to an axial direction of the developer holding member. The developer retrieving member is driven to rotate around an axis parallel to the main scanning direction and configured to retrieve the development agent from the developer holding surface under a retrieving electric field that is generated when a retrieving voltage is applied between the developer retrieving member and the developer holding member.