Abstract: The spin-orbit torque-based random number generator includes a spin torque generation layer including a first spin torque layer and a second spin torque layer, a magnetization-free layer, a tunnel barrier layer, and a magnetization pinned layer, wherein the second spin torque layer is disposed between the magnetization-free layer and the first spin torque layer and generates field-like torque (FLT) and damping-like torque (DLT) related to the magnetization direction of the magnetization-free layer; the first spin torque layer adjusts a torque ratio according to the size of field-like torque to the size of damping-like torque in conjunction with the thickness of the second spin torque layer; in the magnetization-free layer, a magnetization direction is randomly aligned up or down based on the adjusted torque ratio; and a random number is generated based on current that is switched and output based on the randomly aligned magnetization direction.