Abstract: An object of the present invention is to provide a belt tightener that is capable of tightening belts reliably by a smaller force and thus is excellent in operability. A belt take-up mechanism 5 of a belt tightener 100 includes a belt take-up shaft 7, a handle 20 supported about an axis on a body frame 3 so as to be coaxial with this belt take-up shaft 7, first and second one-way clutches 8 and 9 both fixed to the belt take-up shaft 7, a first latch 25 provided on the handle 20 and engageable with and disengageable from the first one-way clutch 8, and a second latch 31 provided on the body frame 3 and engageable with and disengageable from the second one-way clutch 9, and an inner wheel member 11 and an outer wheel member 10 of each one-way clutch 8, 9 and two cover plates 16 that block a space portion between the outer wheel member 10 and the inner wheel member 11 are integrally formed.