A butterfly valve-type throttle valve 10 includes a valve shaft 12 extending across an intake air passage 5 of an internal combustion engine, and a butterfly-type valve body 14 for adjusting a flow rate of an intake air flowing through the intake air passage 5 by rotating in unison with the valve shaft 12. The valve body 14 is constituted by two split members 20, and is configured such that the split members 20 are coupled to each other by a welding 36, which is a coupling that uses no screw, and such that an axial hole 34 for fitting with the valve shaft 12 is formed through the coupling. A gap closing member 16 is provided on a circumferential edge portion of the valve body 14 for closing a gap between the valve body 14 positioned at a fully closed position and a passage wall surface 5a of the intake air passage 5.