A developing apparatus includes a developing container for containing a developer. An amount of the developer in the developing container is 100 2000 (g), and an angle of rest of the developer in said developing container is 20 70 (.degree.). When the developing apparatus develops an electrostatic image having an image density of 100(%), an amount A (g) of the developer in the developing container at the time when a difference between a carrier supply amount per unit time by the supplying device and a carrier discharging amount per unit time through the discharging outlet becomes 5(g/min) or less, and an amount B (g) of the developer in the developing container at the time the carrier discharging amount per unit time becomes 0.5(g/min) or less when said developing apparatus operates without supply of the carrier by said supplying means, satisfy 0.01<(A-B)/A<0.10.