A rotary connector device, wherein: a stator and a rotator , which rotates with respect to the stator concentrically with a steering, are formed; a torque transmitting portion is formed, which is located on a radially internal side of an angle detection rotating body concentrically therewith, is formed into a substantially tubular shape and elongated downward from a lower end of an inner peripheral tube portion of the rotator , rotates together with the rotator , and transmits a rotation torque of the steering to the angle detection rotating body , the angle detection rotating body being located concentrically with a rotation axis of the steering on an inner peripheral side of an angle detection sensor , the angle detection sensor being formed into a ring shape in a plan view, being mounted concentrically with the rotation axis of the steering, and detecting a rotation angle of the steering; fitting portions for fitting to fitting allowance portions, which are formed on at least parts of a circumferential direction of the angle detection rotating body , are formed on the torque transmitting portion ; the fitting portions are each formed into a trench shape notched so as to divide a circumference of the substantially tubular-shaped torque transmitting portion along an axis direction of the steering; the fitting allowance portions include fitting protrusions which protrude radially inward so as to fit to the trench-shaped fitting portions on predetermined opposing portions of an inner peripheral surface of the angle detection rotating body , which oppose each other in a diametrical direction across the rotary center of the angle detection rotating body ; fitting abutting portions of the fitting portions , which fit and abut against the fitting allowance portions, are formed in a shape tapered toward the fitting protrusions ; and the fitting portions and the fitting protrusions abut each other at a point or along a line (TL). a stator and a rotator , which rotates with respect to the stator concentrically with a steering, are formed; a torque transmitting portion is formed, which is located on a radially internal side of an angle detection rotating body concentrically therewith, is formed into a substantially tubular shape and elongated downward from a lower end of an inner peripheral tube portion of the rotator , rotates together with the rotator , and transmits a rotation torque of the steering to the angle detection rotating body , the angle detection rotating body being located concentrically with a rotation axis of the steering on an inner peripheral side of an angle detection sensor , the angle detection sensor being formed into a ring shape in a plan view, being mounted concentrically with the rotation axis of the steering, and detecting a rotation angle of the steering; fitting portions for fitting to fitting allowance portions, which are formed on at least parts of a circumferential direction of the angle detection rotating body , are formed on the torque transmitting portion ; the fitting portions are each formed into a trench shape notched so as to divide a circumference of the substantially tubular-shaped torque transmitting portion along an axis direction of the steering; the fitting allowance portions include fitting protrusions which protrude radially inward so as to fit to the trench-shaped fitting portions on predetermined opposing portions of an inner peripheral surface of the angle detection rotating body , which oppose each other in a diametrical direction across the rotary center of the angle detection rotating body ; fitting abutting portions of the fitting portions , which fit and abut against the fitting allowance portions, are formed in a shape tapered toward the fitting protrusions ; and the fitting portions and the fitting protrusions abut each other at a point or along a line (TL). <EOS>