A seal part includes an elastic body that is in close contact with outer peripheral surfaces of a plurality of wires and an inner peripheral surface of a wire accommodation portion, and a rigid body that has an outer peripheral surface disposed to face the inner peripheral surface of the wire accommodation portion. The rigid body has a plurality of wire through holes allowing wires to coaxially pass through respectively. The elastic body includes first seal portions that respectively correspond to the wire through holes, and that are in close contact with the outer peripheral surfaces of the wires passing through the wire through holes, and a second seal portion that is in close contact with the inner peripheral surface of the wire accommodation portion in the wire accommodation portion.