PURPOSE: A disk brake of a vehicle is provided to prevent vibration of a pad plate during traveling by spacing pad plates from a disk promptly with restoring force of a pad spring and by pressing pad plates with fixing parts of the pad spring, and to manufacture and install the pad spring conveniently by modifying the spring member. CONSTITUTION: A disk brake has a disk rotating with a wheel; first and second pad plates(11,12) contacted to the disk for braking and arranged at both sides of the disk with friction pads; a fixing member fastened in the vehicle body for supporting pad plates; and a pressure unit pressing pad plates to the disk. A pad supporting pin(30) is fastened in the fixing member and penetrated through pad plates. A pad spring(31) is supported with the pad supporting pin and the pad plates to return the pad plates and prevent vibration. The pad spring has a fixing unit(31a) bent and fitted to upper parts of the pad plates to press the pad plates, and a fitting unit(31b) bent and fitted to the pad supporting pin. Vibration of the pad plates is prevented with spacing the pad plates from the disk promptly by restoring force of the pad spring.