DISC BRAKE

A disc brake including a piston driving mechanism. The piston driving mechanism includes an input member extended in a cylinder in a protruding direction of a piston, including a threaded portion formed on a circumferential surface of the input member, and configured to be rotated with transmission of torque from an electric motor; a tubular rotation linear motion member including an engaging threaded portion that is engaged with the threaded portion of the input member, and configured to move in an axial direction of the cylinder by rotation of the input member to transmit a torque of the electric motor to the piston; a tubular support member supported on a caliper main body to be not rotatable and placed on an outer side in a radial direction with respect to the rotation linear motion member; and a rolling element placed between the support member and the rotation linear motion member.