The zoom lens with a wide angle of view, a high zoom ratio and high optical performance includes, in order from an object side to an image side, a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, a third lens unit having a positive refractive power, and a fourth lens unit having a positive refractive power. The second and fourth lens units are moved on an optical axis for zooming. The second lens unit is constituted by, in order from the object side to the image side, three negative lens elements and one positive lens element. The zoom lens satisfies 0.54