To provide a jig for installing an anchor bolt in a partition foundation, which enables the anchor bolts or the single anchor bolt to be accurately installed in a form by simple operations, can bring efficiency to the execution of work for the foundation on a building site, and can shorten a construction period.

One-side ends of paired measuring tapes SC1 and SC2 are held at two points in such a manner that points crossing leveling strings serve as measuring standards, respectively, so that a distance between centers of anchor bolt fitting holes of a crossing form X1 can be measured; and the two points, which sandwich the anchor bolt fitting holes, are located on the respective leveling strings passing through the anchor bolt fitting holes serving as standards for a base plate 5 with which the crossing form X1 is bridged. Consequently, the anchor bolt installing jig 3 can be accurately installed, so that the anchor bolts 2 or the single anchor bolt 2 can be accurately installed in the crossing form X1 by the simple operations, so that the efficiency can be brought to the execution of the work for the foundation on the building site, and so that the construction period can be shortened.