A vehicle door handle device is configured so that, after a frame is assembled to an outer panel of a slide door, a link base, a connecting link, and a hand grip are mounted to the frame. Next, a lever and a cap are mounted to the hand grip and the frame, thereby assembling each component member to the outer panel. When the hand grip is moved through a door opening operation in the same direction as a slide door opening direction, an operation force for releasing a fully closed latch mechanism, which retains the slide door in a fully closed state, is generated. In addition, when the hand grip is moved through a door closing operation in the same direction as a slide door closing direction, an operation force for releasing a fully opened latch mechanism, which retains the slide door in a fully opened state, is generated.