The present invention relates to a holding apparatus which is made to hold a flexible plate wound on a circumferential surface of a holder and more particularly to a holding apparatus suitable for use in the retention of a plate on a circumferential surface of a sleeve of a plate cylinder of a printing machine. A holding apparatus 1 made to hold a plate 5 on a circumferential surface of a holder 4 for the apparatus size reduction comprises a hole section 7 made in the holder along an axial direction of the holder 4, a groove section 8 made by notching the circumferential surface of the holder 4 along the axial direction to establish a connection with the hole section 7 and accept insertion of a leading edge end portion and trailing edge end portion of the plate 5, a tension bar 10 inserted and fitted into the hole section 7 for engaging the trailing edge end portion of the plate 5 and a rotating mechanism 11 provided in the hole section 7 for rotating the tension bar 10.