To provide a method and device for mounting an elastic belt-like ring in prescribed positions where the ring is engaged around plural rollers efficiently and accurately.

The ring 2 is mounted in mounting positions by housing the ring 2 which is held in a shape when it is mounted in the prescribed mounting positions where it is engaged around the plural rollers, housing the ring 2 in a mounting device 1 provided with housing parts 34 and 35 in the width direction of the belt, arranging the mounting device 1 in the position where the ring 2 housed in the housing parts 34 and 35 is approached in opposition to the mounting positions and pushing out the ring 2 housed in the housing parts 34 and 35 to the outside in the width direction of the belt with ejectors 40 and 41.