A developing apparatus includes: an agitating chamber agitating a developer; a developing chamber provided with an inlet to which the developer is supplied from the agitating chamber and an outlet from which the developer is returned to the agitating chamber; a developer carrying member; a rotatable developer supplying member supplying the developer to the developer carrying member; a developer conveying member, provided above the center of rotation of the developer supplying member in the developing chamber, for conveying the developer in a longitudinal direction of the developer carrying member, wherein, in a vertical cross-sectional area of a region vertically above the center of rotation of the developer supplying member of the developing chamber, excluding a developer conveying region by the developer conveying member, a cross-sectional area S1 upstream in the developer conveying direction and a cross-sectional area S2 downstream in the developer conveying direction satisfy a relationship of S1