SEAT BELT RETRACTOR

A seat belt retractor which is mounted in a mounting space formed on a backrest of a seat installed in a vehicle and comprises a spindle module including webbing and a spindle having the webbing wound on the outer surface thereof, wherein the spindle is arranged along the longitudinal direction of the vehicle corresponding to the thickness direction of the backrest in the mounting space, such that by rotating the direction in which the spindle, on which the webbing is wound, is installed, the width in the longitudinal direction mounted on the backrest of the seat can be minimized, thereby making the retractor more slender.