To provide a draft machine, a spinning unit and a spinning machine which can suck in fiber waste surely without falling off of a suction conveying tube when a cradle is opened or shut, and in which unnecessary consumption of air flow caused by a leak of suction air in running is prevented.

A machine comprises roller pairs R, a switching unit 31 and a suction unit 41. The suction unit 41 comprises: a suction inlet 42 to suck in fiber waste at near of a top roller; a first suction conveying tube 43 to convey fiber waste sucked by the suction inlet 42; and a second suction conveying tube 44 provided independently of the first suction conveying tube 43, which is in a connection state in a draft position by contacting with the first suction conveying tube 43, and in a non-connection state in a non-draft position by spacing from the first suction conveying tube 43. The first suction conveying tube 43 and the second suction conveying tube 44 are connected at a downstream side of a roller pair R located at the most downstream position in a draft direction of a fiber bundle F.