Abstract: A level measuring probe for a liquid contained in a reservoir of the type having a detecting element constituted by a conductor having a high temperature coefficient and intended to be immersed in the liquid; and an electrical connection means intended to permit connection of the said detector element to a connector; a plurality of printed circuits disposed in respective parallel strips are provided on an insulating substrate, the assembly forming a flexible film and each circuit having a detecting zone and an electrical connection zone; the film is assembled to a support of, for example, stainless steel; the assembly is out at the edges of the parallel strips.