PURPOSE: To obtain performance of an about ×2 zoom ratio with compact constitution while maintaining superior performance by composing a zoom lens of the 1st W the 2nd lens groups which satisfy conditions of inequalities.

CONSTITUTION: The 1st divergent lens group G1 consisting of at least one negative lens and at least one positive lens and the 2nd lens group G2 which consists of a front group having at least two positive lenses and a rear group having at least one negative lens are provided, and the above-mentioned constitution satisfies conditions expressed in equalities, where f1 and fW are the focal length of the 1st lens group G1 and the composite focal length of the whole system at the wide-angle end, lW is the air gap between the 1st lens group G1 and the 2nd lens group G2 at the wide-angle end, and fZ and fZR are the focal length of the 2nd lens group and the focal length of the rear group in the 2nd lens group G2. Consequently, while the superior performance is maintained, performance of an about ×2 zoom ratio is realized with the simple, compact constitution.