A torque sensor for detecting torque around a predetermined rotation axis, including: a first support body, a second support body, a detection part which connects the first support body and the second support body and which undergoes elastic deformation by exertion of torque to be detected, a detection element which detects elastic deformation occurring at the detection part, and a detection circuit which outputs an electric signal indicating torque around the rotation axis exerted on one of (i) the first support body in a state that a load is applied to the second support body, and (ii) the second support body in a state that a load is applied to the first support body. The detection element includes a capacitive element which includes a displacement electrode fixed to a displacement part and a fixing electrode opposing the displacement electrode. The detection circuit outputs the electric signal indicating the exerted torque based on fluctuation in capacitance value of the capacitive element.