The zoom lens comprises five or more groups of lens pieces, namely, the foremost or first lens group of positive refractive power located the closest to an object, the succeeding second lens group of negative refractive power, the third lens group of positive refractive power, the fourth lens group of positive refractive power, and the fifth lens group all arranged in this order, and if any, the rearmost lens group(s) closer to the imaging plane than the fifth lens group. The zoom lens meets requirements as defined in the conditional expression regarding a combined magnification of the fifth lens group and, if any, the rearmost lens group(s) closer to the imaging plane than the fifth lens group while the zoom lens is taking a telephoto position.