A rotation restriction mechanism for maintenance, wherein the rotation restriction mechanism for maintenance is adapted to be mounted to a disc brake which operates such that brake pads of a brake caliper are pressed against a disc rotor which rotates with an axle, thereby regulating the rotation of the disc rotor, the rotation restriction mechanism for maintenance characterized in that it comprises: a connection part adapted to be connected by screwing to a screw connection member which is provided radially inward of the brake caliper and protrudes from the disc rotor; and a regulation part which extends radially outward from the connection part and, when the disc rotor rotates, is brought into contact with the brake caliper to prevent the rotation of the disc rotor, in the disc rotor, an outer peripheral section which is a radially outer section and on which the brake caliper is disposed is thinner than an inner peripheral section which is a radially inner section and on which the connection part is disposed, and the regulation part comprises: an extending portion extending radially outward from the connection part; and a leg portion extending from an end part of the extending portion to reach the outer peripheral section. wherein the rotation restriction mechanism for maintenance is adapted to be mounted to a disc brake which operates such that brake pads of a brake caliper are pressed against a disc rotor which rotates with an axle, thereby regulating the rotation of the disc rotor, the rotation restriction mechanism for maintenance characterized in that it comprises: a connection part adapted to be connected by screwing to a screw connection member which is provided radially inward of the brake caliper and protrudes from the disc rotor; and a regulation part which extends radially outward from the connection part and, when the disc rotor rotates, is brought into contact with the brake caliper to prevent the rotation of the disc rotor, in the disc rotor, an outer peripheral section which is a radially outer section and on which the brake caliper is disposed is thinner than an inner peripheral section which is a radially inner section and on which the connection part is disposed, and the regulation part comprises: an extending portion extending radially outward from the connection part; and a leg portion extending from an end part of the extending portion to reach the outer peripheral section. a connection part adapted to be connected by screwing to a screw connection member which is provided radially inward of the brake caliper and protrudes from the disc rotor; and a regulation part which extends radially outward from the connection part and, when the disc rotor rotates, is brought into contact with the brake caliper to prevent the rotation of the disc rotor, in the disc rotor, an outer peripheral section which is a radially outer section and on which the brake caliper is disposed is thinner than an inner peripheral section which is a radially inner section and on which the connection part is disposed, and the regulation part comprises: an extending portion extending radially outward from the connection part; and a leg portion extending from an end part of the extending portion to reach the outer peripheral section. an extending portion extending radially outward from the connection part; and a leg portion extending from an end part of the extending portion to reach the outer peripheral section.