A spindle device comprising: a rotating shaft which has a plurality of turbine blades installed in a circumferential direction and is configured to mount a mounting object on a tip; a housing which accommodates the rotating shaft ; a radial bearing which is attached to the housing and floatingly supports the rotating shaft in a non-contact manner with respect to the housing by supplying gas; a thrust bearing which is attached to the housing and supports the rotating shaft in a thrust direction with respect to the housing by supplying gas; a case which is arranged to surround an outer peripheral surface of the housing ; and a plurality of O-rings which are arranged between the housing and the case and support the housing with respect to the case , wherein: the spindle device rotationally drives the rotating shaft by ejecting gas to the plurality of turbine blades ; at least one O-ring is arranged between a center (C1) of the radial bearing and the center of gravity (G) of the rotating shaft in an axial direction of the rotating shaft ; characterized in that a distance (B) from a rear end surface of the thrust bearing to a center of gravity (G) of the rotating shaft is larger than a diameter (A) of an area center (C2) of the thrust bearing ; and that two O-rings are arranged on the rear end side of the housing from the center (C1) of the radial bearing . a rotating shaft which has a plurality of turbine blades installed in a circumferential direction and is configured to mount a mounting object on a tip; a housing which accommodates the rotating shaft ; a radial bearing which is attached to the housing and floatingly supports the rotating shaft in a non-contact manner with respect to the housing by supplying gas; a thrust bearing which is attached to the housing and supports the rotating shaft in a thrust direction with respect to the housing by supplying gas; a case which is arranged to surround an outer peripheral surface of the housing ; and a plurality of O-rings which are arranged between the housing and the case and support the housing with respect to the case , wherein: the spindle device rotationally drives the rotating shaft by ejecting gas to the plurality of turbine blades ; at least one O-ring is arranged between a center (C1) of the radial bearing and the center of gravity (G) of the rotating shaft in an axial direction of the rotating shaft ; characterized in that a distance (B) from a rear end surface of the thrust bearing to a center of gravity (G) of the rotating shaft is larger than a diameter (A) of an area center (C2) of the thrust bearing ; and that two O-rings are arranged on the rear end side of the housing from the center (C1) of the radial bearing . the spindle device rotationally drives the rotating shaft by ejecting gas to the plurality of turbine blades ; at least one O-ring is arranged between a center (C1) of the radial bearing and the center of gravity (G) of the rotating shaft in an axial direction of the rotating shaft ; characterized in that a distance (B) from a rear end surface of the thrust bearing to a center of gravity (G) of the rotating shaft is larger than a diameter (A) of an area center (C2) of the thrust bearing ; and that two O-rings are arranged on the rear end side of the housing from the center (C1) of the radial bearing . <EOS>