Provided are: an impact fastening tool which prevents a torque detector from missing a signal and extends service life by adopting a fixed connector that prevents the trouble of being instantaneously separated (bounced) from a rotating electrode by intermittent impacts and has a shape allowing the progression of friction to be delayed structurally; and a torque tester. Both end portions of the fixed connector are fixed, and at least two protrusion portions are formed between the both end portions. The rotating electrode is disposed between one protrusion portion and the other protrusion portion such that the rotating electrode contacts the fixed connector at two or more points or in a line form. A signal required for the torque detecting means is transmitted through the contact between the rotating electrode and the fixed connector.