A connector, comprising: a first connector; and a second connector, wherein the connector is configured by the first connector and the second connector which are fitted and electrically connected to each other, the first connector includes: a first housing, and a projecting portion that projects from an end portion of the first housing and extends toward the second connector in a fitting direction of the first connector and the second connector, the second connector includes: a terminal (T1, T2) extending in the fitting direction, a cap including a cover portion that covers a surface of the terminal (T1, T2) on a side of the first connector, a rotating shaft provided on an edge portion of the cover portion, and a contact portion extending to an opposite side to the cover portion from the rotating shaft and abutable on the projecting portion, and a second housing including a guide groove that guides the projecting portion and supporting the rotating shaft, and the guide groove extends along the fitting direction from an opening portion on the side of the first connector with respect to the rotating shaft toward an opposite side to the first connector, characterized in that the second housing includes a flat plate portion extending from a position corresponding to the rotating shaft toward the side of the first connector in the fitting direction, and the guide groove is provided in the flat plate portion and includes a tapered portion that decreases in width from the side of the first connector toward the opening portion. a first connector; and a second connector, wherein the connector is configured by the first connector and the second connector which are fitted and electrically connected to each other, the first connector includes: a first housing, and a projecting portion that projects from an end portion of the first housing and extends toward the second connector in a fitting direction of the first connector and the second connector, a first housing, and a projecting portion that projects from an end portion of the first housing and extends toward the second connector in a fitting direction of the first connector and the second connector, the second connector includes: a terminal (T1, T2) extending in the fitting direction, a cap including a cover portion that covers a surface of the terminal (T1, T2) on a side of the first connector, a rotating shaft provided on an edge portion of the cover portion, and a contact portion extending to an opposite side to the cover portion from the rotating shaft and abutable on the projecting portion, and a second housing including a guide groove that guides the projecting portion and supporting the rotating shaft, and a terminal (T1, T2) extending in the fitting direction, a cap including a cover portion that covers a surface of the terminal (T1, T2) on a side of the first connector, a rotating shaft provided on an edge portion of the cover portion, and a contact portion extending to an opposite side to the cover portion from the rotating shaft and abutable on the projecting portion, and a second housing including a guide groove that guides the projecting portion and supporting the rotating shaft, and the guide groove extends along the fitting direction from an opening portion on the side of the first connector with respect to the rotating shaft toward an opposite side to the first connector, characterized in that the second housing includes a flat plate portion extending from a position corresponding to the rotating shaft toward the side of the first connector in the fitting direction, and the guide groove is provided in the flat plate portion and includes a tapered portion that decreases in width from the side of the first connector toward the opening portion.