A zoom lens in which when the magnification is changed in the range from a wide-angle position to a telephoto position in infinite object point focusing, spacing between a first lens unit, with negative refractive power as a whole, having a negative lens and a positive lens, and a second lens unit, with positive refractive power as whole, having a positive lens and a cemented lens component constructed with a positive lens and a negative lens, is narrowed and spacing between the second lens unit and a third lens unit, a single positive lens component, is widened, and the zoom lens satisfies the following condition: 2.1<|.beta.2T|<2.8 where .beta.2T is the magnification of the whole of the second lens unit at the telephoto position in the infinite object point focusing.