To secure high molding precision and high machining quality by devising a machining method in molding an archwire slot liner for use in orthodontic treatment by roller machining.

This manufacturing method for the archwire slot liner is formed by: bending a belt-shaped sheet or wire rod W into an arcuate cross section; contracting the bottom part to push its thickness aside to the left/right, bending it while preventing the decrease of the wall thickness or increasing the wall thickness of corner parts, and molding it into a U-shaped cross section or a recessed cross section; further pressurizing it by upper/lower/left/right rollers to form it into a final recessed cross section; and cutting it.