A pad pressing spring which is mounted on a pad of a disc brake by causing a pinching portion to pinch a pad back plate is configured as follows. An elastic arm which presses the pad in a disc rotor normal-rotating direction continuously extends from a base end side of the pinching portion, and the elastic arm has a configuration in which, when a load exceeding a predetermined value is applied in a direction opposite to a direction in which a pad is pressed, a tip end side of the elastic arm comes into contact with a lateral surface of the pad back plate or the pinching portion, and thus a spring constant of the pad pressing spring increases compared to a spring constant in a state where a load exceeding the predetermined value is not applied.