Tub corner sealing element for sealing a bath or shower tub corner with respect to a building part and a connecting surface of a tub support, wherein the tub corner sealing element comprises a flat, watertight base sealing part and a watertight, right-angled tub sealing part, wherein the base sealing part has a tub-side surface for sealed connection to a connecting surface of a bath or shower tub and a building-side surface for sealed connection to the building part; said tub sealing member comprising a flat tub rim leg having a tub rim sealing surface for sealingly connecting with a lower connecting surface of a tub rim, and a flat tub support leg having a tub support sealing surface for sealingly connecting with the connecting surface of the tub support; wherein the tub edge leg and the tub support leg are connected to each other in a watertight manner and enclose a right angle; wherein an end face of the tub edge leg and an end face of the tub support leg are connected in a watertight manner to the tub side of the flat base sealing part; wherein the flat base sealing part extends in a flat state with respect to a corner of the tub sealing part formed by the tub edge leg and the tub support leg on the side of the tub edge sealing surface of the tub edge leg and on the opposite side of the tub support sealing surface of the tub support leg by a predetermined minimum length, preferably by at least five centimetres, characterised in that the base sealing part extends over at least three quarters resp. 270 degrees with respect to the corner of the tub sealing part; and, wherein the tub edge leg extends on the side of the tub support leg facing away from the tub support sealing surface along the entire length thereof. wherein the base sealing part has a tub-side surface for sealed connection to a connecting surface of a bath or shower tub and a building-side surface for sealed connection to the building part; said tub sealing member comprising a flat tub rim leg having a tub rim sealing surface for sealingly connecting with a lower connecting surface of a tub rim, and a flat tub support leg having a tub support sealing surface for sealingly connecting with the connecting surface of the tub support; wherein the tub edge leg and the tub support leg are connected to each other in a watertight manner and enclose a right angle; wherein an end face of the tub edge leg and an end face of the tub support leg are connected in a watertight manner to the tub side of the flat base sealing part; wherein the flat base sealing part extends in a flat state with respect to a corner of the tub sealing part formed by the tub edge leg and the tub support leg on the side of the tub edge sealing surface of the tub edge leg and on the opposite side of the tub support sealing surface of the tub support leg by a predetermined minimum length, preferably by at least five centimetres, characterised in that the base sealing part extends over at least three quarters resp. 270 degrees with respect to the corner of the tub sealing part; and, wherein the tub edge leg extends on the side of the tub support leg facing away from the tub support sealing surface along the entire length thereof.