A zoom lens has a field view of 60° to 70° at a wide-angle end, a magnification change ratio of about five to six times, and a small number of component lenses, enables retraction to a compact size when not in use, provides high resolution, and is compatible with a compensation function for zoom lens vibrations. Comprised are, in order from an object side, a first lens unit (G1) of positive optical power, a second lens unit (G2) of negative optical power, a third lens unit (G3) of positive optical power, and a fourth lens unit (G4) of positive optical power. When zooming from the wide-angle end to a telephoto end, the first lens unit (G1) and the second lens unit (G2) move so as to trace a convex path toward an image side, and the third lens unit and the fourth lens unit (G4) move monotonously toward an object side.