An illumination light beam forming device, including a first light source unit projecting a ring shaped light beam group, a second light source unit projecting light beams including a case the light beams being group, a combining unit for combining the light beam group projected from the first light source unit and light beams projected from the second light source unit, in which the combing unit includes a reflecting part formed to reflect one of the light beam groups, a transmitting part disposed able to transmit the other one of the light beam groups, and light beams projected from the second light source unit are disposed at an internal side of the light beam groups projected from the first light source unit when the two light beam groups are viewed from a plane including the reflecting part.