Zoom lens and apparatus using the same

A zoom lens according to the present invention includes, in order from the object 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 negative refractive power, and a fourth lens unit having a positive refractive power. During a magnification change from the wide-angle end through the telephoto end, the first lens unit and the fourth lens unit shift from the image-surface side toward the object side, a space between the first lens unit and the second lens unit increases, and spaces between individual lens units change. During a focusing from an object at the infinite distance onto an object at a near distance, the second lens unit and the third lens unit individually shift independently.