1. A vibration-proof zoom lens for preventing deviation of an image of a subject when vibration of camera occurs, said image of the subject being formed on an image plane, said zoom lens comprising: a positive first lens group fixed at a side of said subject; a negative second lens group disposed between said first lens group and said image plane so as to be movable along an optical axis of said zoom lens, said second lens group moving toward said image plane to change a magnification from a wide-angle end to a telephoto end; a positive third lens group disposed between said second lens group and said image plane, said third lens group including a first subgroup, a second subgroup and a third subgroup, and said second subgroup being moved in a plane perpendicular to said optical axis to correct a blur of said image at a time of the vibration of said camera; a positive fourth lens group disposed between said third lens group and said image plane so as to be movable along said optical axis, said fourth lens group being moved to correct variation of said image plane, which is caused in accordance with a change of the magnification, and to perform focusing; and a positive fifth lens group fixed between said fourth lens group and said image plane.