The invention relates to a clamping/releasing flange that can be used to hold a plate panel on a machining stage, comprising a supporting body (1), a frame (2) that is position-adjustable in relation to the supporting body (1) in the clamping/releasing direction (SD), and a plurality of lugs (P1, P2) used for clamping and holding by being pressed into one of the lateral edges of the panel. The flange comprises, in a housing (20) formed in the frame (2), a mobile support (21) for supporting said clamping and holding lugs (P1, P2) at least partially emerging through a through-hole (22) of the frame, that ends in said housing (20), and means (3) for the continuous control of the movement, clamping, holding and release of the lugs in the clamping direction (SD). The invention is applicable to machine-tool equipment.