An image forming apparatus includes a developing apparatus for developing an electrostatic image with a developer comprising at least a toner and a first external additive, the developing apparatus including a plurality of developing devices, containing toners different in color or lightness from each other, in which at least two developing devices contain a dark color toner and a light color toner which have an identical hue and different lightnesses and the developing device containing the light color toner is subjected to a developing operation prior to another developing device; a first transfer apparatus for sequentially transferring toner images, which have been developed by the plurality of developing devices, onto an intermediary transfer member; and a second transfer apparatus for transferring the toner images from the intermediary transfer member all together onto a transfer medium The first external additive includes particles having an aspect ratio of not less than 1.0 and not more than 1.5 and a number-average particle size of not less than 0.06 .mu.m and not more than 0.3 .mu.m, and has a coverage thereof with respect to the light color toner larger than that with respect to the dark color toner in a transferred state on the intermediary transfer member.