To produce a screw which has sufficient mechanical strength and high reliability and scarcely develops wrinkle and laminating fault in the screw part.

A thread-rolling apparatus provided with a thread-rolling oil heating means 12 for heating the thread-rolling oil supplied into a screw blank 5 and thread-rolling dies 2, 3 to a prescribed temp., is used, and the screw blank 5 preheated to the prescribed temp., is set to the thread-rolling dies 2, 3, and screw thread is thread-rolled on the outer peripheral surface of the screw blank while supplying the thread-rolling oil heated to a prescribed temp. into the screw blank and the thread-rolling dies.