A disk brake comprising: a brake disk, a moving disk, a fixed disk, a mounting base, a guide rod, a fixed rod, first and second levers, a fixed plate, and first and second spring clamps. Here, one end of the fixed rod is fixed to a plane of the moving disk, the other end of the fixed rod passes through the fixed disk and is fixed to one end of the first/second lever, and the other end of the first/second lever is fixed to the circumferential surface of the fixed disk on the center line of the fixed disk; the fixed plate is fixed to either the guide rod or the mounting base; one end of the first/second spring clamp is connected to the fixed plate, and the other end of the first/second spring clamp is clamped at the middle position between the first and second levers.