The zoom lens which is compact and has high optical performance over the entire zoom range includes in order from an object side to an image side, a first lens unit having a negative refractive power, a second lens unit having a positive refractive power, and a third lens unit having a positive refractive power. Distances between the first to third lens units are varied during zooming. The second lens unit includes a lens element whose image side surface has a concave shape, a most object side positive lens element and a most image side positive lens element. Conditions of 0.4