A holding structure of a terminal-equipped electric wire comprising: a connector comprising: a housing comprising a first main body portion which is configured to be inserted into an attachment hole of an outer wall of a box-shaped body from an outer side of the box-shaped body that is an attachment target; a bus bar that is held by the housing, having an L-shape and including a main body portion embedded in the housing and extending in a front-rear direction which corresponds to the direction in which the housing is inserted into the attachment hole, and a fastened portion disposed on an inner side of the box-shaped body with respect to the outer wall is bent from a front end portion of the main body portion and is exposed to an outside from the housing and is configured to be connected to a terminal fitting by fastening using a bolt; and a nut that is held by the housing with a gap between the nut and the fastened portion, the gap allowing insertion of the terminal fitting, and the nut being configured to engage with the bolt to fasten the fastened portion and the terminal fitting inserted into the gap together, wherein the holding structure of terminal-equipped electric wire comprises further a terminal-equipped electric wire in which the terminal fitting is attached to an end of an electric wire and is provided in the inner side of the box-shaped body, wherein the electric wire of the terminal-equipped electric wire extends toward the connector in a curved state, and the terminal fitting is configured to be disposed in the gap between the fastened portion of the bus bar and the nut, and in a state in which the bolt is not fastened to the nut, the terminal fitting is pressed against and brought into contact with at least one of the fastened portion and the nut by an elastic force generated by the curved electric wire, and is held in the gap by a frictional force generated between the terminal fitting and the at least one of the fastened portion and the nut, wherein the terminal fitting includes a circular flat plate portion in which a bolt through hole is formed, wherein the gap is slightly larger than a plate thickness of the flat plate portion of the terminal fitting. a housing comprising a first main body portion which is configured to be inserted into an attachment hole of an outer wall of a box-shaped body from an outer side of the box-shaped body that is an attachment target; a bus bar that is held by the housing, having an L-shape and including a main body portion embedded in the housing and extending in a front-rear direction which corresponds to the direction in which the housing is inserted into the attachment hole, and a fastened portion disposed on an inner side of the box-shaped body with respect to the outer wall is bent from a front end portion of the main body portion and is exposed to an outside from the housing and is configured to be connected to a terminal fitting by fastening using a bolt; and a nut that is held by the housing with a gap between the nut and the fastened portion, the gap allowing insertion of the terminal fitting, and the nut being configured to engage with the bolt to fasten the fastened portion and the terminal fitting inserted into the gap together, wherein the holding structure of terminal-equipped electric wire comprises further a terminal-equipped electric wire in which the terminal fitting is attached to an end of an electric wire and is provided in the inner side of the box-shaped body, wherein the electric wire of the terminal-equipped electric wire extends toward the connector in a curved state, and the terminal fitting is configured to be disposed in the gap between the fastened portion of the bus bar and the nut, and in a state in which the bolt is not fastened to the nut, the terminal fitting is pressed against and brought into contact with at least one of the fastened portion and the nut by an elastic force generated by the curved electric wire, and is held in the gap by a frictional force generated between the terminal fitting and the at least one of the fastened portion and the nut, wherein the terminal fitting includes a circular flat plate portion in which a bolt through hole is formed, wherein the gap is slightly larger than a plate thickness of the flat plate portion of the terminal fitting.