PURPOSE: To provide a method for producing a distortion-free woven fabric by using a loom provided with plural series of weft-feeding devices, and further to provide a twist direction error-detecting device used therefor.

CONSTITUTION: A spiral guide 4 is formed in a spiral form different from the rotation direction of a yarn when unwound from a raw yarn, pirn 6 and is spirally expanded, while forming a space 4a allowing the passage of the yarn 1. A yarn-detecting sensor 5 for detecting the passage of the yarn is disposed at the space part 4a of the spiral guide. When a yarn different in the twist direction is set, the yarn-detecting sensor 5 can thereby be operated by the rotation of the unwound yarn to surely detect the difference in the twist.