A spindle device comprising: a rotary shaft, a housing, a fixed-side bearing having an inner ring fitted onto one end portion of the rotary shaft and an outer ring fixed to the housing; a bearing sleeve disposed at the other end portion of the rotary shaft, and fitted to the housing with clearance; and a free-side bearing having an inner ring fitted onto the other end portion of the rotary shaft, and an outer ring fitted to the bearing sleeve, and rotatably supporting the rotary shaft in cooperation with the fixed-side bearing, characterized in that the bearing sleeve includes at least annular carbon fiber composite material having the same axial length as the bearing sleeve, and (a) the bearing sleeve includes an annular outer metal member disposed at an outer diameter side thereof and having an outer peripheral surface fitted to the housing, an annular inner metal member disposed at an inner diameter side thereof and having an inner peripheral surface fitted to the outer ring, and the carbon fiber composite material disposed between the annular outer metal member and the annular inner metal member, or (b) the bearing sleeve includes an annular outer metal member disposed at an outer diameter side thereof and having an outer peripheral surface fitted to the housing, and the carbon fiber composite material disposed on an inner side of the annular outer metal member and having an inner peripheral surface fitted to the outer ring, or (c) the bearing sleeve includes the carbon fiber composite material disposed at an outer diameter side thereof and having an outer peripheral surface fitted to the housing, and an annular inner metal member disposed on an inner side of the carbon fiber composite material and having an inner peripheral surface fitted to the outer ring. a rotary shaft, a housing, a fixed-side bearing having an inner ring fitted onto one end portion of the rotary shaft and an outer ring fixed to the housing; a bearing sleeve disposed at the other end portion of the rotary shaft, and fitted to the housing with clearance; and a free-side bearing having an inner ring fitted onto the other end portion of the rotary shaft, and an outer ring fitted to the bearing sleeve, and rotatably supporting the rotary shaft in cooperation with the fixed-side bearing, characterized in that the bearing sleeve includes at least annular carbon fiber composite material having the same axial length as the bearing sleeve, and (a) the bearing sleeve includes an annular outer metal member disposed at an outer diameter side thereof and having an outer peripheral surface fitted to the housing, an annular inner metal member disposed at an inner diameter side thereof and having an inner peripheral surface fitted to the outer ring, and the carbon fiber composite material disposed between the annular outer metal member and the annular inner metal member, or (b) the bearing sleeve includes an annular outer metal member disposed at an outer diameter side thereof and having an outer peripheral surface fitted to the housing, and the carbon fiber composite material disposed on an inner side of the annular outer metal member and having an inner peripheral surface fitted to the outer ring, or (c) the bearing sleeve includes the carbon fiber composite material disposed at an outer diameter side thereof and having an outer peripheral surface fitted to the housing, and an annular inner metal member disposed on an inner side of the carbon fiber composite material and having an inner peripheral surface fitted to the outer ring. (a) the bearing sleeve includes an annular outer metal member disposed at an outer diameter side thereof and having an outer peripheral surface fitted to the housing, an annular inner metal member disposed at an inner diameter side thereof and having an inner peripheral surface fitted to the outer ring, and the carbon fiber composite material disposed between the annular outer metal member and the annular inner metal member, or (b) the bearing sleeve includes an annular outer metal member disposed at an outer diameter side thereof and having an outer peripheral surface fitted to the housing, and the carbon fiber composite material disposed on an inner side of the annular outer metal member and having an inner peripheral surface fitted to the outer ring, or (c) the bearing sleeve includes the carbon fiber composite material disposed at an outer diameter side thereof and having an outer peripheral surface fitted to the housing, and an annular inner metal member disposed on an inner side of the carbon fiber composite material and having an inner peripheral surface fitted to the outer ring.