An image forming apparatus includes an image bearing member for bearing and conveying an electrostatic image; a first developer carrying member for carrying and conveying a developer toward a first developing position; and a second developer carrying member for carrying and conveying the developer toward a second developing position, wherein when a time period required for a movement of the developer carried and conveyed by the first developer carrying member and the second developer carrying member from the first developing position through the developer delivering portion to the second developing position is assigned TA, and a time period required for a movement of the developer on the image bearing member from the first developing position to the second developing position is assigned TB, and wherein respective driving speeds of the image bearing member, the first developer carrying member, and the second developer carrying member are controlled so that TA and TB are different values.