Abstract: In a zoom lens device of a two-lens group structure, positive and negative lens groups are sequentially arranged from a photographing field side. The zoom lens device has a controller for controlling a rear focusing operation for moving the negative lens group on a high magnification side. The controller also controls one of an entire drawing-out focusing operation for moving the positive and negative lens groups, and a front focusing operation for moving the positive lens group on a low magnification side. The high and low magnification sides are respectively set to telescopic and wide angle sides. A focal length of the zoom lens device is increased on the high magnification side and is decreased on the low magnification side. Thus, a zoom ratio is increased and a lens drawing-out amount is reduced on the telescopic side so that the zoom lens device can be made compact.