A rotation body suitable for a rotary connector device, comprising: an annular member configured to be assembled to a fixed body, the annular member being rotatable about a rotation axis with respect to the fixed body; and a connector connected to the annular member, wherein the connector includes: a cover including a first wall extending from the annular member in an axial direction parallel to the rotation axis and formed with a space therein; a conductor electrically connected to a cable conducting wire and disposed in the space; and a holding member that is attached to the cover in the space and holds the conductor and includes a main body portion and a holding portion, wherein the main body portion and the holding portion are detachable, and the main body portion is attached to the connector in the space with the holding portion attached, the holding member includes, in the first wall, an exposed portion exposed to the outside of the space, the cover and the holding member include a restriction structure that restricts foreign matter from entering the space through the exposed portion, and the restriction structure includes a first protrusion and a first recess in which the first protrusion is fitted, characterized in that the first protrusion of the restriction structure protrudes in a direction orthogonal to the first wall, and that the main body portion includes a fitting portion, the cover includes a fitted portion provided in the space, and the holding member is attached to the cover in the space by fitting the fitting portion to the fitted portion in the space along the axial direction. an annular member configured to be assembled to a fixed body, the annular member being rotatable about a rotation axis with respect to the fixed body; and a connector connected to the annular member, wherein the connector includes: a cover including a first wall extending from the annular member in an axial direction parallel to the rotation axis and formed with a space therein; a conductor electrically connected to a cable conducting wire and disposed in the space; and a holding member that is attached to the cover in the space and holds the conductor and includes a main body portion and a holding portion, wherein the main body portion and the holding portion are detachable, and the main body portion is attached to the connector in the space with the holding portion attached, the holding member includes, in the first wall, an exposed portion exposed to the outside of the space, the cover and the holding member include a restriction structure that restricts foreign matter from entering the space through the exposed portion, and the restriction structure includes a first protrusion and a first recess in which the first protrusion is fitted, characterized in that the first protrusion of the restriction structure protrudes in a direction orthogonal to the first wall, and that the main body portion includes a fitting portion, the cover includes a fitted portion provided in the space, and the holding member is attached to the cover in the space by fitting the fitting portion to the fitted portion in the space along the axial direction. a cover including a first wall extending from the annular member in an axial direction parallel to the rotation axis and formed with a space therein; a conductor electrically connected to a cable conducting wire and disposed in the space; and a holding member that is attached to the cover in the space and holds the conductor and includes a main body portion and a holding portion, wherein the main body portion and the holding portion are detachable, and the main body portion is attached to the connector in the space with the holding portion attached, the holding member includes, in the first wall, an exposed portion exposed to the outside of the space, the cover and the holding member include a restriction structure that restricts foreign matter from entering the space through the exposed portion, and the restriction structure includes a first protrusion and a first recess in which the first protrusion is fitted, characterized in that the first protrusion of the restriction structure protrudes in a direction orthogonal to the first wall, and that the main body portion includes a fitting portion, the cover includes a fitted portion provided in the space, and the holding member is attached to the cover in the space by fitting the fitting portion to the fitted portion in the space along the axial direction.