Abstract: A toroidal type stepless speed changer including input and output disks (10) and (12), power rollers (20) provided between the disks with supporting shafts (28) thereof outwardly protruding, a single movable ring (30) with which the outer ends of the power roller supporting shafts (28) are engaged, the single movable ring being movable in the direction of the disk center shaft (14) with turning thereof being restricted, and a single adjustment belt (48) capable of making reciprocal motion in its turning (circumferential) direction so as to move the movable ring (30) along to disk center shaft. By the movement of the movable ring (30) in the disk center shaft direction that is caused by the reciprocal motion of the adjustment belt (48), the inclination of all the power roller supporting shaft is varied, thus changing the rotational speed between the input and output disks.