A cover that includes a main body covering to be attached to a connector main body including an insertion hole through which a bolt for attaching to a device can be inserted; and a bolt covering that is formed integrally with the main body covering and is for covering a head of the bolt inserted through the insertion hole, wherein: the main body covering includes: a cylindrical covering for covering the connector main body; and a fixing member for fixing the covering in a fastened state to the connector main body, the bolt covering is formed so as to extend outward in a radial direction of the covering from an outer circumferential surface of the covering, and the bolt covering is an integral product made of elastic synthetic resin that is formed integrally with the covering.