To provide a brake mechanism capable of more safely braking rotation of a rotor in which load in a radial direction is supported by a radial bearing and a bearing device having the brake mechanism.

A static pressure gas bearing device 1A includes: a static pressure gas bearing 3 which supports load in a radial direction R of a rotor 2; a disc-like eddy current generation part 4 which is attached to a side of one end 21 of the rotor 2 and formed of a nonmagnetic good conductor or a feebly-magnetic good conductor; a permanent magnet 5 disposed on a side of one end surface 41 of the eddy current generation part 4; and a magnet movement mechanism 6 which guides the permanent magnet 5 to the radial direction R of the rotor 2. When stopping the rotation of the rotor 2, the permanent magnet 5 is moved to a position P2 by the magnet movement mechanism 6, a magnetic line M of the permanent magnet 5 is irradiated on the one end surface 41 of the eddy current generation part 4 and an eddy current according to the change in magnetic flux density due to the rotation of the rotor 2 is generated in the eddy current generation part 4. Therefore, the rotation of the rotor 2 is attenuated by converting rotation energy of the rotor 2 into heat energy.