A cloth edge position detecting device comprising: a cloth edge sensor configured to output a voltage corresponding to a cloth edge position, the cloth edge position being a position of a cloth edge of a workpiece cloth to be fed in a cloth feeding direction such that the cloth edge is disposed along the cloth feeding direction; and a control section (71, 72) configured to detect the cloth edge position in a direction orthogonal to the cloth feeding direction based on the voltage output from the cloth edge sensor, characterized in that the control section (71, 72) is configured to determine that a position (Pos) at which a voltage change exceeding a cloth edge determining threshold (Ve) appears first in the direction from the inner side to the outer side of the workpiece cloth across the cloth edge in a sensing region of the cloth edge sensor is the cloth edge position, and in that the control section (71, 72) is configured to determine a cloth condition as a fluff when the position (Pos) determined as the cloth edge position changes by a first threshold (|ON-START|) or more in the direction from the inner side to the outer side of the workpiece cloth within a first cloth feeding time (T s) or during feeding of the workpiece cloth by a first cloth feeding amount and/or to determine a cloth condition as a notch when the position (Pos) determined as the cloth edge position changes by a first threshold (|ON-START|) or more in the direction from the outer side to the inner side of the workpiece cloth within a first cloth feeding time (T s) or during feeding of the workpiece cloth by a first cloth feeding amount. a cloth edge sensor configured to output a voltage corresponding to a cloth edge position, the cloth edge position being a position of a cloth edge of a workpiece cloth to be fed in a cloth feeding direction such that the cloth edge is disposed along the cloth feeding direction; and a control section (71, 72) configured to detect the cloth edge position in a direction orthogonal to the cloth feeding direction based on the voltage output from the cloth edge sensor, characterized in that the control section (71, 72) is configured to determine that a position (Pos) at which a voltage change exceeding a cloth edge determining threshold (Ve) appears first in the direction from the inner side to the outer side of the workpiece cloth across the cloth edge in a sensing region of the cloth edge sensor is the cloth edge position, and in that the control section (71, 72) is configured to determine a cloth condition as a fluff when the position (Pos) determined as the cloth edge position changes by a first threshold (|ON-START|) or more in the direction from the inner side to the outer side of the workpiece cloth within a first cloth feeding time (T s) or during feeding of the workpiece cloth by a first cloth feeding amount and/or to determine a cloth condition as a notch when the position (Pos) determined as the cloth edge position changes by a first threshold (|ON-START|) or more in the direction from the outer side to the inner side of the workpiece cloth within a first cloth feeding time (T s) or during feeding of the workpiece cloth by a first cloth feeding amount.