A zoom lens comprises, in order from its object side, a first lens group of positive refracting power, a second lens group of negative refracting power, and a third lens group of positive refracting power located on an image side with respect to the second lens group. Upon zooming from the wide-angle end to the telephoto end, the spacing between the first lens group and the second lens group grows wider at the telephoto end than at the wide-angle end, and the spacing between the second lens group and the third lens group becomes narrower at the telephoto end than at the wide-angle end. The first lens group comprises a negative lens and a positive lens, and the number of the negative lens in the first lens group is only one. At least one positive lens in the first lens group satisfies the following conditions (1) and (2): 1.80