the first lens unit is composed of two lens elements, in order from the object side to the image side, comprising a first lens element that has a concave surface at least on the image side and that has negative optical power and a second lens element that has a convex surface at least on the object side and that has positive optical power,

the second lens unit, in order from the object side to the image side, comprises a first cemented lens element fabricated by cementing a third lens element and a fourth lens element having optical power of mutually different signs and a second cemented lens element fabricated by cementing a fifth lens element and a sixth lens element having optical power of mutually different signs,

in zooming from a wide-angle limit to a telephoto limit, all of the first lens unit, the second lens unit and the third lens unit move along an optical axis, and

the following conditions (1) and (I-2) are satisfied:

5.0<αi_W<20.0  (1)

n₁₁≧1.9  (I-2)

(here, 3.2<f_T/f_W and ω_W>35)

where,

αi_W is an incident angle of a principal ray to an image sensor at a maximum image height at a wide-angle limit (defined as positive when the principal ray is incident on a light acceptance surface of the image sensor in a state of departing from the optical axis),

n₁₁ is a refractive index of the first lens element to the d-line,

ω_W is a half view angle (°) at a wide-angle limit,

f_T is a focal length of the entire system at a telephoto limit, and

f_W is a focal length of the entire system at a wide-angle limit.