PURPOSE: To obtain the subject hard-twist yarn having excellent crape extent and quality comparable to silk and good operation stability and handleability by applying hard-twist to a specific polyester yarn and heat-treating the yarn under specific condition to set the twist.

CONSTITUTION: The objective hard-twist yarn having a dry-heat shrinking stress of 0.03-0.15 g/d (preferably 0.05-0.12 g/d) at 120-240°C can be produced by applying hard-twist to a polyester yarn composed mainly of ethylene terephthalate unit and having a hot-water shrinkage of ≤4% and a dry-heat shrinking stress of 0.2-0.3 g/d at 120-240°C and heat-treating the polyester yarn at 65-85°C for 20-40min to set the twist. The polyester yarn having a hot-water shrinkage of ≤4% can be produced by a high-speed spinning process at a spinning speed of 6,500 m/min.