There are provided a first lens group having a negative optical power as a
whole, second and third lens groups having positive optical powers as a
whole, which are located in this order from the object side. These lens
groups are all configured to be movable in the optical axis direction
during magnification. The first lens group is constituted by a bi-concave
lens having a negative optical power and a positive meniscus lens which
is convex at the object side thereof, which are located in this order
from the object side. The second lens group is constituted by a bi-convex
lens having a positive optical power and a bi-concave power having a
negative optical power, which are located in this order from the object
side and bonded to each other to constitute a cemented lens. The third
lens group is constituted by a bi-convex lens having a positive optical
power. The first and fifth lenses are double-aspherical lenses formed
from resin and the third and fourth lenses are single-aspherical lenses.