Rotor and centrifuge

Provided are a rotor and a centrifuge with which operability of a rotor cover is improved by a simple structure with a small number of components. A rotor 100 has, on the outer surface of a nut holder 20 mounted to a rotor body 10, a holder outer surface notch 24 that is parallel to a central axis 90z, and a holder outer surface groove 25 that is provided in the circumferential direction and is continuous to the holder outer surface notch 24. The rotor 100 has, on the inner surface of a handle 40 mounted on a rotor cover 30, a handle inner claw 45 that protrudes toward the central axis 90z. The handle inner claw 45 is opposed to the holder outer surface notch 24, the handle 40 is inserted in the nut holder 20 in the direction of the central axis 90z in a phase in which the handle inner claw 45 does not interfere with the outer surface of the nut holder 20, and the nut holder 20 and the handle 40 are rotated relative to each other, thereby causing the handle inner claw 45 to enter the holder outer surface groove 25 to restrict vertical movement of the handle 40 with respect to the nut holder 20.