At least one exemplary embodiment is directed to a zoom lens configured to correct chromatic aberration and having a high optical performance over the entire zoom range. The zoom lens includes, in order from an object side to an image side, a first lens unit of positive refractive power, a second lens unit of negative refractive power, and a third lens unit of positive refractive power. During zooming, an interval between respective adjacent lens units varies. The third lens unit includes an optical element made of a solid material having an Abbe number (.nu.d) and a relative partial dispersion (.theta.gF) satisfying the following condition: .theta.gF-(-1.665.times.10.sup.-7.nu.d.sup.3+5.213.times.10.sup.-5.nu.d.s- up.2-5.656.times.10.sup.-3.nu.d +0.755)>0.