To provide a mounting jig and a mounting method for an insert, in which the mounting jig can be installed by one operator and can be mounted and demounted simply and surely.

A screw section 21 screwed to the tapped hole 10 of the insert 1 is formed at the front end of a screw rod 2, and a screw section 22 screwed to a clamping member 6 is formed at the rear end. A collar plate 3 is installed to the screw rod, so as to be brought into contact with the inside of forms 4, and a ring member 5 is mounted on the screw rod so as to be positioned outside the forms. A screw-rod holding section is formed at the rear end of the screw rod, the screw rod is held by the screw-rod holding section, and the insert is secured to the forms together with the screw rod, by clamping the clamping member and pinching the forms between the clamping member and the collar plate.