The present invention relates to a socket wrench of simple structure, easy to manufacture, having minimum size and weight on the whole so that one can tighten up or loosen easily, with small strength, a bolt for use in fixing the tire wheel of compact cars such as a jeep and a passenger car to a hub. The socket wrench of the present invention is comprised of an operation axis which is rotated by operation of a handle, a cylinder on the inner surface of which a saw-toothed orbital gear is formed around, a first transmission which is installed within the cylinder for reducing the speed of the torque of the operation axis firstly while strengthening the torque, a second transmission for reducing the speed of the torque secondly while strengthening the torque, thereby rotating, with strong force, a socket for receiving a bolt to be tightened or loosened, and an auxiliary socket which is fixed to a bracket that is extended from a front cap installed in the line end of the cylinder, for receiving other bolt adjacent to the bolt to be tightened or loosened so that the cylinder is not vibrated upon usage.