To improve the efficiency of work for mounting helical insert parts, ensure easy removal of a tongue, after cut, from a tap hole and avoid damage to the corner of the tap hole.

A helical insert inserting jig 2 includes a rod jig mainbody 4 having a diameter smaller than the inner diameter of helical insert parts and a handle provided on the side of the head of the jig mainbody 4 and protruded toward both sides of the jig mainbody 4. At the tip of the jig mainbody 4, a groove 8 is formed extending perpendicular to the extending direction of the jig mainbody 4, wider than the tongue of the helical insert parts and opening toward the tip of the jig mainbody. Two magnets 10 are mounted neat the tip of the jig mainbody 4 with the groove 8 interposed therebetween. The magnets 10 are embedded in the tip of the jig mainbody 4, and portions of the respective magnets 10 are exposed into the groove 8 beyond the opposed wall faces 14 of the groove 8 and the exposed faces 12 of the magnets 10 are formed nearly as high as the wall faces 14 of the groove 8.