To obtain a compact standard zoom lens having a wide viewing angle by respectively providing a 1st lens group and a 2nd lens group with at least one aspherical surface and satisfying a specified condition.

The 1st lens group is constituted of two lenses being the 1st lens having negative power and the 2nd lens having positive power in turn from an object side. Then, the 1st lens group and the 2nd lens group are respectively provided with at least one aspherical surface so as to satisfy the condition of an expression. In the expression, f1 shows the focal distance of the 1st lens group, (fw) shows the focal distance of a whole system at the minimum focal distance end and (ft) shows the focal distance of the whole system at the maximum focal distance end. Besides, TDt shows a distance to the top of the surface of the 2nd lens group on the most image side from the top of the surface of the 1st lens on the object side at the maximum focal distance end, x2 shows the moving amount of the 2nd lens group in an optical axis direction (provided that the movement to the image side is defined as positive) a zooming time, BFw shows a back focus at the minimum focal distance end and Ymax shows the maximum image height.