Abstract: A testing device for fixing-load verification is configured such that a coupler (2) having, formed so as to protrude therefrom, a contact part (251/252) that comes into contact with a fixing surface is fixed at a rod-like torque detection unit of a rod-like torque wrench main body (1) and a means (3) for engaging with a fixing bolt (B) is fixed to a side part of the coupler. A side tip part of the engagement means (3) has an open and recessed part (30) for accommodating the fixing bolt (B) from the side, and a protruding part of the fixing bolt (B) is accommodated inside this open and recessed part (30) and the fixing bolt is locked by the deepest part of the open and recessed part (30) or the vicinity thereof. Thus, the testing device for fixing-load verification can be attached to a fixing bolt under test using a simple procedure even when work is being carried out with limited work space.