Abstract: A holding device of a torque tester is disclosed. The holding device is disposed on a platform, which has a driving device for the disposition of the working end of a torque wrench. The holding device holds the holder of the torque wrench. The holding device includes a board, a swinging body, and a sliding body. The board is disposed on the platform and has an axle element. The swinging body includes a bottom board with an axle hole for the axle element to go through. The swinging body is thus pivotally disposed on the board. Both sides of the bottom board are provided with a stop wall, respectively. The two stop walls and the bottom board form an accommodating passage. The sliding body slides inside the accommodating passage. The sliding body has a fixing structure to hold the holder. The sliding body is allowed to move inside the accommodating passage relative to the swinging body.