A disk brake has a mount and a pad. The pad has a guide portion and outer and inner push bearing portions on a disk rotor rotation outlet side. The mount has a support portion to support the guide portion movably in a rotor axial direction. The outer and inner push bearing portions are provided on each position outwardly or inwardly of the rotor rotation outlet side guide portion in the radial direction of the rotor, and project toward the mount in the radial direction of the rotor to abut against the mount. The outer push bearing portion has an abutment surface to abut against the mount on a tangent to an outer peripheral side in a central position of the outer peripheral side of a friction surface of the pad radially outwardly in the radial direction of the rotor, or in a position outwardly of the tangent.