A method for producing a basin integrated in a work surface, named the receiving plane, comprising an upper surface and a lower surface, according to which method - the receiving plane is pierced right through and an opening adapted to receive the basin is formed, - a mould is used, comprising: • a first lower shell of generally concave shape, named the lower shell, adapted to bear on the lower surface of the receiving plane and • at least one upper shell of generally convex shape, named the upper shell(s) (13, 13a, 13b), adapted to bear on the upper surface of the receiving plane and form with the lower shell a moulding cavity, named impression, with the shape of the basin to be obtained, - the receiving plane is installed in the mould so as to clamp the periphery of the opening of the receiving plane between the lower shell and an upper shell in such a way that at least part of the edge of the opening constitutes a continuous peripheral wall of the mould connecting the lower shell to the upper shell, characterised in that - the mould is adapted to enable a thermoplastic synthetic material to be injected, - the lower shell has a concave zone surrounded by a convex rim extending along the edge of the opening, inside and at a distance from the edge, projecting relative to the level of the lower surface of the receiving plane in the direction of its upper surface, said rim being adapted to enable the formation of a peripheral skirt of the basin between the edge of the opening and said rim during the moulding-on of the basin, - and in that a thermoplastic synthetic material is injected into the impression so as to form a basin moulded onto the receiving plane. - the receiving plane is pierced right through and an opening adapted to receive the basin is formed, - a mould is used, comprising: • a first lower shell of generally concave shape, named the lower shell, adapted to bear on the lower surface of the receiving plane and • at least one upper shell of generally convex shape, named the upper shell(s) (13, 13a, 13b), adapted to bear on the upper surface of the receiving plane and form with the lower shell a moulding cavity, named impression, with the shape of the basin to be obtained, • a first lower shell of generally concave shape, named the lower shell, adapted to bear on the lower surface of the receiving plane and • at least one upper shell of generally convex shape, named the upper shell(s) (13, 13a, 13b), adapted to bear on the upper surface of the receiving plane and form with the lower shell a moulding cavity, named impression, with the shape of the basin to be obtained, - the receiving plane is installed in the mould so as to clamp the periphery of the opening of the receiving plane between the lower shell and an upper shell in such a way that at least part of the edge of the opening constitutes a continuous peripheral wall of the mould connecting the lower shell to the upper shell, characterised in that - the mould is adapted to enable a thermoplastic synthetic material to be injected, - the lower shell has a concave zone surrounded by a convex rim extending along the edge of the opening, inside and at a distance from the edge, projecting relative to the level of the lower surface of the receiving plane in the direction of its upper surface, said rim being adapted to enable the formation of a peripheral skirt of the basin between the edge of the opening and said rim during the moulding-on of the basin, - and in that a thermoplastic synthetic material is injected into the impression so as to form a basin moulded onto the receiving plane.