The spindle device 1 is provided with: a housing 10 formed with a support hole 10a; a spindle 12 which is supported to rotate freely about an axis within the support hole 10a of the housing 10 and of which distal end is attached with a tool T; a drive motor 20 for rotating the spindle 12 about the axis, the drive motor 20 being configured by a rotor 22 arranged to rotate freely on an outer circumferential surface of the spindle 12 and a stator 23 fixedly provided on an inner circumferential surface of the support hole 10a of the housing 10; an electromagnetic clutch 30 for transmitting intermittently a drive force of the drive motor 20 to the spindle 12; and a controlling device 40 for controlling an operation of the drive motor 20 and that of the electromagnetic clutch 30.