A lightweight spring type torque limiter is proposed, which performs the torque limiting function using the binding force applied from a coil spring to an inner ring inserted in an outer annular member. The inner ring (2) is rotatably inserted in the outer annular member (1). The coil spring (3) is fitted around the inner ring (2) and includes a small-diameter portion (3a) tightened against the radially outer surface of the inner ring (2). The coil spring (3) has hooks (3c and 3d) at the respective ends thereof which are coupled to the outer annular member (1) and an adjusting ring (4) rotatably fitted in the outer annular member (1), respectively. The inner ring (2) is formed by injection-molding a thermoplastic resin to reduce the weight of the inner ring and thus the weight of the entire torque limiter, compared to conventional inner rings, which are made of metal, and conventional torque limiters including an inner ring made of metal.