Abstract: An improved developing material supplying device for use in a developing apparatus of an electrophotographic copying machine which includes a developing material supplying roller having at least one developing material measuring recess formed by cutting the peripheral surface of the supplying roller into flat shape and rotatably provided at a developing material supplying opening of a developing material storage tank, a driving mechanism for the supplying roller, a developing material measuring regulating member provided where the recess of the supplying roller at the supplying opening is rotated from inside to outside of the storage tank, and a shield member capable of covering the entire surface of the recess and provided where the recess at the supplying opening moves from outside to inside of the storage tank.