PURPOSE: To lighten a step roller or a roller blade by using synthetic resin wheels instead of aluminum metal wheels used for a step roller or a roller blade.

CONSTITUTION: A synthetic resin roller is provided with synthetic resin wheels 1 around an outer circumference of a bearing which slides around a shaft, a plurality of air cooling holes 2 are provided adjacent to the bearing, and a plurality of bridging holes 4 are provided between ribs which are arranged between the air cooling holes 2 and a synthetic resin tip circumference part 5. Whole the circumferential edge for separation prevention is provided at the end part of a side wall including the bridging holes 4 except the air cooling holes 2 so as to be integrally formed with elastic synthetic resin.