Provided is a force sensor which is capable of inhibiting breakage of a strain body, and improving reliability, even if the rigidity of the strain body differs in the axial direction. A force sensor 10 according to an embodiment of the present application has a main body 11 which is cylindrical. A cylindrical movable body 12 is capable of moving with respect to the main body, and has at least three circular openings 13 provided to the circumference. A strain body 16 is fixed to the main body and the movable body, and is capable of deforming in accordance with the movement of the movable body. A strain sensor 16a is provided to the strain body. First stoppers 14 are provided inside each of the openings, and are provided with first outer circumferential surfaces having a first external diameter that is smaller than the diameter of the openings. A cylindrical second stopper 24 is provided a first distance away from a first inner circumferential surface of the main body, and is provided with a second outer circumferential surface having a second external diameter that is smaller than the diameter of the first inner circumferential surface.