A spinning machine comprising: a plurality of spinning units; each of the spinning units including an air spinning device configured to generate a yarn by performing a spinning operation of applying twists to a fiber bundle by using air; and a supplying device configured to supply an agent-containing air that contains agent to the fiber bundle or the yarn at a position between a position upstream of an inlet of the air spinning device for the fiber bundle and an outlet of the air spinning device for the yarn, wherein the supplying device includes a supply piping (63A; 63B) configured to allow a flow of the agent-containing air therethrough, the supply piping (63A; 63B) having a first end connected to the air spinning device of the spinning unit, wherein the supplying device includes an air piping that extends along an arrangement direction of the spinning units, wherein a second end of the supply piping (63A; 63B) is connected to the air piping, and wherein the air piping is supplied with agent stored in an agent tank and with pressurized air fed by an air compressing and feeding device characterized in that the supply piping (63A; 63B) is arranged so as to rise towards the first end of the supply piping (63A; 63B) in a direction of a flow of the agent-containing air in the supply piping (63A; 63B), wherein the air piping is arranged at a lower level than the air spinning device in a height direction of the spinning unit, wherein the supply piping is arranged at a lower level than the air spinning device in the height direction and so as to rise, in the entire region from the second end to the first end thereof, in the direction of flow of the agent-containing air. a plurality of spinning units; each of the spinning units including an air spinning device configured to generate a yarn by performing a spinning operation of applying twists to a fiber bundle by using air; and a supplying device configured to supply an agent-containing air that contains agent to the fiber bundle or the yarn at a position between a position upstream of an inlet of the air spinning device for the fiber bundle and an outlet of the air spinning device for the yarn, wherein the supplying device includes a supply piping (63A; 63B) configured to allow a flow of the agent-containing air therethrough, the supply piping (63A; 63B) having a first end connected to the air spinning device of the spinning unit, wherein the supplying device includes an air piping that extends along an arrangement direction of the spinning units, wherein a second end of the supply piping (63A; 63B) is connected to the air piping, and wherein the air piping is supplied with agent stored in an agent tank and with pressurized air fed by an air compressing and feeding device characterized in that the supply piping (63A; 63B) is arranged so as to rise towards the first end of the supply piping (63A; 63B) in a direction of a flow of the agent-containing air in the supply piping (63A; 63B), wherein the air piping is arranged at a lower level than the air spinning device in a height direction of the spinning unit, wherein the supply piping is arranged at a lower level than the air spinning device in the height direction and so as to rise, in the entire region from the second end to the first end thereof, in the direction of flow of the agent-containing air.