A waste yarn emission amount output device comprising: an output section that calculates and outputs a waste yarn emission amount from each of devices in a textile machine, the devices emitting waste yarns; and a display unit that displays a waste yarn emission amount outputted by the output section characterized in that: the textile machine includes a yarn feed part from which a yarn is drawn out, a winding part that winds a yarn fed from the yarn feed part, to form a package, and a yarn joining device that performs yarn joining when a yarn is broken at a location between the yarn feed part and the winding part; the winding part includes a winding drum that comes into contact with the package to cause slave rotation of the package; and when the yarn joining device performs yarn joining, the output section calculates a waste yarn emission amount based on a rotation angle through which the winding drum is rotated in a direction reverse to a direction in which the winding drum is rotated in order to draw out a yarn from the winding part at a time of winding or in that: the textile machine includes a yarn feed part from which a yarn is drawn out, a winding part that winds a yarn fed from the yarn feed part, to form a package, and a yarn joining device that performs yarn joining when a yarn is broken at a location between the yarn feed part and the winding part; and when the yarn joining device performs yarn joining, the output section calculates a waste yarn emission amount based on a rotation angle through which the package is rotated in a direction reverse to a direction in which the package is rotated in order to draw out a yarn from the winding part at a time of winding. an output section that calculates and outputs a waste yarn emission amount from each of devices in a textile machine, the devices emitting waste yarns; and a display unit that displays a waste yarn emission amount outputted by the output section the textile machine includes a yarn feed part from which a yarn is drawn out, a winding part that winds a yarn fed from the yarn feed part, to form a package, and a yarn joining device that performs yarn joining when a yarn is broken at a location between the yarn feed part and the winding part; a yarn feed part from which a yarn is drawn out, a winding part that winds a yarn fed from the yarn feed part, to form a package, and a yarn joining device that performs yarn joining when a yarn is broken at a location between the yarn feed part and the winding part; the winding part includes a winding drum that comes into contact with the package to cause slave rotation of the package; and when the yarn joining device performs yarn joining, the output section calculates a waste yarn emission amount based on a rotation angle through which the winding drum is rotated in a direction reverse to a direction in which the winding drum is rotated in order to draw out a yarn from the winding part at a time of winding the textile machine includes a yarn feed part from which a yarn is drawn out, a winding part that winds a yarn fed from the yarn feed part, to form a package, and a yarn joining device that performs yarn joining when a yarn is broken at a location between the yarn feed part and the winding part; and a yarn feed part from which a yarn is drawn out, a winding part that winds a yarn fed from the yarn feed part, to form a package, and a yarn joining device that performs yarn joining when a yarn is broken at a location between the yarn feed part and the winding part; and when the yarn joining device performs yarn joining, the output section calculates a waste yarn emission amount based on a rotation angle through which the package is rotated in a direction reverse to a direction in which the package is rotated in order to draw out a yarn from the winding part at a time of winding.