A zoom lens system ZL comprising, in order from an object side: a first lens group G1 having positive refractive power; a second lens group G2 having negative refractive power; a third lens group G3 having positive refractive power; a fourth lens group G4 having negative refractive power; and a fifth lens group G5 having positive refractive power; upon zooming the first lens group G1 being fixed with respect to an image plane in the direction of the optical axis, upon focusing at least a portion of the third lens group G3 being moved along the optical axis, and the zoom lens system satisfying predetermined conditions. An optical apparatus is equipped with the zoom lens system, and there is a method for manufacturing the zoom lens system.