A zoom lens includes, sequentially from an object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, and a fourth lens group. During zooming from a wide angle position to a telephoto position, the interval between the first lens group and the second lens group increases, the interval between the second lens group and the third lens group decreases, and an interval between the third lens group and the fourth lens group varies. The fourth lens group includes, sequentially from the object side, a first sub-lens group having a positive refractive power, a second sub-lens group having a negative refractive power, and a third sub-lens group. The second sub-lens group of the fourth lens group is moved along an optical axis to perform focusing.