PURPOSE: To provide a small zoom lens capable of simplifying the structure of a lens barrel and focusing at a short distance while increasing a variable power and improving the performance.

CONSTITUTION: This zoom lens is provided with a focusing lens group Gs moving along the optical axis at the time of focusing at a short distance, a lens group Ga arranged adjacent to the object side of the focusing lens group Gs and a lens group Gb arranged adjacent to the image side of the focusing lens group Gs, at the time of varying the power from the wide-angle end to the telescopic end, the lens group Ga and the lens group Gb are integrally moved, the focusing lens group Gs is relatively moved to the lens group Ga and the lens group Gb, one lens group among the lens group Ga and the lens group Gb has a positive focal distance, the other lens group has a negative focal distance and, by representing the focal distance of the lens group Ga by fa and the focal distance of the lens group Gb by fb, the condition: -0.6<(fa+ fb)/(fa-fb)<0.4 is satisfied.