An inner focusing type telephoto zoom lens includes a fixed first lens group having a positive refractive power, the first lens group being disposed closest to the object, a second lens group having a negative refractive power, the second lens group being movable along an optical axis for focusing, a fixed third lens group having a positive refractive power, a fourth lens group having a negative refractive power, the fourth lens group being movable along the optical axis for zooming, a fifth lens group having a positive refractive power, the fifth lens group being movable along the optical axis relative to the fourth lens group, and a fixed sixth lens group having a positive refractive power. The zoom lens satisfies the following condition:0.4