A zoom lens comprises a first lens unit that does not move for zooming and that has a positive refractive power, a second lens unit that is configure to move to an image side during zooming from a wide angle end to a telephoto end and that has a negative refractive power, a third lens unit that is configured to reduce image plane variation due to zooming, and a fourth lens unit that does not move for zooming. The fourth lens unit comprises a fourth-F unit, a fourth-B1 unit, and a fourth-B2 unit. The average Abbe number of positive lens and negative lenses in the fourth-B1 unit and the average Abbe number of positive negative lenses in the fourth-B2 unit are set appropriately.