Imaging lens device has a zoom lens system and an image sensor. The zoom lens system has a first reflecting surface, a first movable lens unit, an aperture stop, a second reflecting surface, a second movable lens unit. A first reflecting surface bends a first optical axis which is an incident optical axis of the zoom lens system 90 degrees into a second optical axis. A second reflecting surface bends the second optical axis 90 degrees into a third optical axis. The first optical axis, the second optical axis and the third optical axis are mutually perpendicular. The first movable lens unit and the aperture stop are disposed on the second optical axis. The second movable lens unit is disposed on the third optical axis. During zooming, the first and second reflecting surfaces and the aperture stop are stationary; the first and second movable lens units are moved, respectively.