Abstract: This invention is intended to effect torque control of high accuracy by detecting the oil pressure at the time of the generation of a pulse which forms the basis of the generated torque for a torque wrench and using the data thus obtained the effect torque control. Oil pressure pulses generated in a pulse generating mechanism 3 by the rotation of an air motor 1 are transmitted to a hydraulic cylinder 4 by a piston 33, a rod 36 and a piston 35. In addition, a pressure sensor 5 installed in the hydraulic cylinder 34 detects the oil pressure pulses and its signal is used to switch a switching valve 7, whereupon a stopping switching valve 9 and a stopping differential pressure valve 8 are successively switched, stopping the feeding of air to the air motor 1 while cutting of the passage of electric current from a battery 61 to an electric control circuit 6.