To protect a brake device inside of a disc wheel.

The disc wheel 14 is equipped with: a rim part 18 for mounting a tire 20 to hold; a disc part 16 mounted to an axle 28 to hold the rim part 18; a plurality of opening parts 34 arranged in a row in the circumferential direction of the disc part 16; a plurality of covers 36 which are provided on the plurality of opening parts 34 respectively, and open or close the opening parts 34; and an electric magnet 48 which independently opens or closes the plurality of covers 36 respectively. A wheel speed sensor 32 detects a rotary position of the disc wheel 14. An ECU100 controls an open or close state of the cover 36 by operating the electric magnet 48, based on the detection value of the wheel speed sensor 32.