The present invention provides, a roller-type one-way clutch comprising an annular outer race provided at its inner periphery with a cam surface, an inner race spaced apart from the outer race in a radially inner diameter side and disposed in coaxial with the outer race for a relative movement therewith and having an annular outer peripheral track surface, a plurality of rollers disposed between the outer race and the inner race and adapted to transmit torque between the outer peripheral track surface and the cam surface, a cage for holding the plurality of rollers, and a C-shaped annular spring for biasing the rollers toward a direction in which the rollers are engaged by the cam surface, through the cage, and wherein the C-shaped annular spring is assembled in a diameter-enlarged condition.