A cup holder, comprising: a base adapted to be fixed to an attached portion; a lid body including an outer surface which becomes a design surface and an inner surface edged by a surrounding wall; the lid body provided switchably between a closed position and an open position by turning relative to the base, overlapped with the base in the closed position, and supporting a cup from a lower side thereof in the open position so as to receive a bottom of the cup; an arm turnably attached to the lid body and having lower piece portions; a holder supported by the arm, and moving in association with turning of the lid body to become a housed state, in which the holder is housed between the lid body and the base, when the lid body is in the closed position, and to become a used state, in which the holder controls a lateral movement of the cup, when the lid body is in the open position, and a pair of first pivotally supporting portions turnably connecting the arm to a corresponding portion of the holder, and a pair of second pivotally supporting portions turnably connecting the arm to a corresponding portion of the lid body, characterised in that each of the pair of second pivotally supporting portions includes a pair of protruding piece portions (14, 16) spaced apart from each other and formed on the base, and a piece portion is provided to stand on left and right on a back side of the inner surface of the lid body, and the lower piece portion is disposed between the protruding piece portions (14, 16), and the piece portion is located between the lower piece portion and the protruding piece portion (14, 16). a base adapted to be fixed to an attached portion; a lid body including an outer surface which becomes a design surface and an inner surface edged by a surrounding wall; the lid body provided switchably between a closed position and an open position by turning relative to the base, overlapped with the base in the closed position, and supporting a cup from a lower side thereof in the open position so as to receive a bottom of the cup; an arm turnably attached to the lid body and having lower piece portions; a holder supported by the arm, and moving in association with turning of the lid body to become a housed state, in which the holder is housed between the lid body and the base, when the lid body is in the closed position, and to become a used state, in which the holder controls a lateral movement of the cup, when the lid body is in the open position, and a pair of first pivotally supporting portions turnably connecting the arm to a corresponding portion of the holder, and a pair of second pivotally supporting portions turnably connecting the arm to a corresponding portion of the lid body, characterised in that each of the pair of second pivotally supporting portions includes a pair of protruding piece portions (14, 16) spaced apart from each other and formed on the base, and a piece portion is provided to stand on left and right on a back side of the inner surface of the lid body, and the lower piece portion is disposed between the protruding piece portions (14, 16), and the piece portion is located between the lower piece portion and the protruding piece portion (14, 16).