The present invention carries out developer elimination suitably in a constitution wherein the feed capacity of a first feed screw (25) for a developer for a region facing an elimination opening (40) for eliminating the developer is low. The first feed screw (25) has blades thereof cut away in a first region that includes a part facing the elimination opening (40). Thus, the feed capacity for the developer in the first region is lower than the feed capacity for the developer in a second region adjacent to the first region. As an acquisition unit, a moisture detection unit detects developer moisture as information concerning the amount of charge in the developer. As a control means, a CPU carries out control such that the drive speed for driving feed screws (25, 26) is faster in the case of the developer moisture being a second moisture which is greater than a first moisture than in the case of the developer moisture being the first moisture on the basis of developer moisture (H) detected by the moisture detection unit.