An electric disc brake is disclosed. An electric disc brake comprises a caliper housing configured to include a cylinder at which a piston is installed to be reciprocally movable by a brake hydraulic pressure, an adjuster arranged inside the piston, a pushrod provided inside the cylinder, an actuator configured to decelerate a rotational force according to an activation of a motor to output the decelerated rotational force through an output gear so as to pressurize the piston, and a ramp unit installed inside the cylinder and configured to receive the decelerated rotational force from the actuator to pressurize the pushrod to the piston so as to prevent rotation of the pushrod.