In a machine tool spindle device, a draw bar is arranged inside a center hole of a spindle, and a disc spring is arranged inside a spring member arrangement space between the draw bar and the center hole. A draw bar inner pipe is inserted inside a through hole of the draw bar, and the interior of the draw bar inner pipe is used as a coolant passage. A gap between the draw bar inner pipe and the through hole is used as an air passage for supplying the purge air, and the interior of the spring member arrangement space is used as a coolant supply passage for supplying coolant to cooling jackets of the spindle.