To provide a sheath pipe holding jig facilitating the operation of positioning a sheath pipe.

The sheath pipe holding jig 10A is mounted to a foundation formation form 5 with concrete placed inside, and holds a sheath pipe 3 in position inside the form 5. The jig includes a leveling string contact portion 133 including two faces 133A and 133B which make contact with two orthogonally arranged leveling strings 101 and 110 through predetermined lengths, and a guide member 13A for positioning the jig 10A relative to the form 5. By simply bringing the two faces 133A and 133B into contact with the two leveling strings 101 and 110, the installed position of the jig 10A can easily be determined. Thus, the operation of positioning the sheath pipe 3 is facilitated.