A bearing device comprising: a rolling bearing which rotatably supports a rotating shaft; a housing which externally covers the rolling bearing in a radial direction of the rotating shaft; a damping member which is disposed inside the housing in the radial direction with a gap between the housing and the damping member and is provided so as not to be displaceable with respect to an outer ring of the rolling bearing in the radial direction and a circumferential direction of the rotating shaft; and a damper which is provided between the housing and the damping member to support the damping member such that the damping member can be displaceable with respect to the housing in an axial direction of the rotating shaft, and absorbs displacement in the radial direction of the rotating shaft generated in the damping member, wherein the damping member includes a bearing holding portion which is provided outside the outer ring of the rolling bearing in the radial direction of the rotating shaft and a preload portion which elastically presses the outer ring in the axial direction of the rotating shaft, wherein the preload portion includes a preload portion main body which is integrally formed with the bearing holding portion and a preload spring which urges the damping member in the axial direction of the rotating shaft, characterized in that the preload portion main body includes a protrusion which extends inward in the radial direction of the rotating shaft and a locking hole which is formed on an end portion of the preload portion main body on a side opposite to the bearing holding portion in the axial direction of the rotating shaft, the housing includes a projection portion which faces the protrusion in the axial direction of the rotating shaft to interpose the preload spring between the protrusion and the projection portion, the projection portion is disposed such that a slight gap is formed between the first sleeve and the projection portion in the axial direction of the rotating shaft, and includes a through-hole at a position facing the locking hole, and a detent pin which is inserted into the locking hole and the through-hole and restricts a relative rotation between the housing and the damping member in the circumferential direction of the rotating shaft is provided. a rolling bearing which rotatably supports a rotating shaft; a housing which externally covers the rolling bearing in a radial direction of the rotating shaft; a damping member which is disposed inside the housing in the radial direction with a gap between the housing and the damping member and is provided so as not to be displaceable with respect to an outer ring of the rolling bearing in the radial direction and a circumferential direction of the rotating shaft; and a damper which is provided between the housing and the damping member to support the damping member such that the damping member can be displaceable with respect to the housing in an axial direction of the rotating shaft, and absorbs displacement in the radial direction of the rotating shaft generated in the damping member, wherein the damping member includes a bearing holding portion which is provided outside the outer ring of the rolling bearing in the radial direction of the rotating shaft and a preload portion which elastically presses the outer ring in the axial direction of the rotating shaft, wherein the preload portion includes a preload portion main body which is integrally formed with the bearing holding portion and a preload spring which urges the damping member in the axial direction of the rotating shaft, characterized in that the preload portion main body includes a protrusion which extends inward in the radial direction of the rotating shaft and a locking hole which is formed on an end portion of the preload portion main body on a side opposite to the bearing holding portion in the axial direction of the rotating shaft, the housing includes a projection portion which faces the protrusion in the axial direction of the rotating shaft to interpose the preload spring between the protrusion and the projection portion, the projection portion is disposed such that a slight gap is formed between the first sleeve and the projection portion in the axial direction of the rotating shaft, and includes a through-hole at a position facing the locking hole, and a detent pin which is inserted into the locking hole and the through-hole and restricts a relative rotation between the housing and the damping member in the circumferential direction of the rotating shaft is provided.