Composing, in order from an object side along the optical axis, a first lens group having positive refractive power, and at least one lens group; upon varying magnification, an interval between the first lens group and a lens group at an image side of the first lens group and adjacent thereto being varied, said first lens group comprising a focusing lens group which is moved along the optical axis for focusing and a vibration reducing lens group that is movable to include a component in a direction perpendicular to the optical axis, thereby providing a an excellent optical performance upon focusing.