A supporting member for thermoinsulating tiles of gas turbine combustion chambers, comprising an elongated plate, having a coupling head at a first end, the coupling head being structured to couple with a thermoinsulating tile and having an inner coupling surface and an outer surface; wherein the outer surface of the coupling head is at least partly coated with a protective coating comprising: a protective metal layer made of MCrAlY alloy applied to the coupling head, M being cobalt or nickel, or a combination of cobalt and nickel; and a thermal barrier layer, applied to the protective metal layer and made of a ceramic material; characterized in that the elongated plate and the coupling head are made of γ' phase precipitation hardening nickel alloy; wherein the MCrAlY alloy has a composition selected from the group consisting of: Ni between 29% and 31% by weight, Cr between 27% and 29% by weight, Al between 7.5% and 7.8% by weight, Y between 0.5% and 0.7% by weight, Si between 0.3% and 0.7% by weight; Ni between 30% and 37% by weight, Cr between 18% and 25% by weight, Al between 7% and 9% by weight, Y between 0.1% and 0.7% by weight; Co between 21% and 23% by weight, Cr between 16% and 18% by weight, Al between 12% and 13% by weight, Y between 0.5% and 0.7% by weight, Si between 0.3% and 0.5% by weight, Hf between 0.2% and 0.3% by weight; Co between 11% and 13% by weight, Cr between 20% and 22% by weight, Al between 10.5% and 11.5% by weight, Y between 0.3% and 0.5% by weight, Re between 1.5% and 2.5% by weight; Co between 24% and 26% by weight, Cr between 16% and 18% by weight, Al between 9.5% and 11% by weight, Y between 0.3% and 0.5% by weight, Re between 1% and 1.8% by weight; Co between 23% and 25% by weight, Cr between 16% and 18% by weight, Al between 9.5% and 11% by weight, Y between 0.3% and 0.5% by weight, Ir between 1.1% and 1.5% by weight, balance Ni; and wherein the γ' phase precipitation hardening nickel alloy contains molybdenum. a protective metal layer made of MCrAlY alloy applied to the coupling head, M being cobalt or nickel, or a combination of cobalt and nickel; and a thermal barrier layer, applied to the protective metal layer and made of a ceramic material; characterized in that the elongated plate and the coupling head are made of γ' phase precipitation hardening nickel alloy; wherein the MCrAlY alloy has a composition selected from the group consisting of: Ni between 29% and 31% by weight, Cr between 27% and 29% by weight, Al between 7.5% and 7.8% by weight, Y between 0.5% and 0.7% by weight, Si between 0.3% and 0.7% by weight; Ni between 30% and 37% by weight, Cr between 18% and 25% by weight, Al between 7% and 9% by weight, Y between 0.1% and 0.7% by weight; Co between 21% and 23% by weight, Cr between 16% and 18% by weight, Al between 12% and 13% by weight, Y between 0.5% and 0.7% by weight, Si between 0.3% and 0.5% by weight, Hf between 0.2% and 0.3% by weight; Co between 11% and 13% by weight, Cr between 20% and 22% by weight, Al between 10.5% and 11.5% by weight, Y between 0.3% and 0.5% by weight, Re between 1.5% and 2.5% by weight; Co between 24% and 26% by weight, Cr between 16% and 18% by weight, Al between 9.5% and 11% by weight, Y between 0.3% and 0.5% by weight, Re between 1% and 1.8% by weight; Co between 23% and 25% by weight, Cr between 16% and 18% by weight, Al between 9.5% and 11% by weight, Y between 0.3% and 0.5% by weight, Ir between 1.1% and 1.5% by weight, balance Ni; Ni between 29% and 31% by weight, Cr between 27% and 29% by weight, Al between 7.5% and 7.8% by weight, Y between 0.5% and 0.7% by weight, Si between 0.3% and 0.7% by weight; Ni between 30% and 37% by weight, Cr between 18% and 25% by weight, Al between 7% and 9% by weight, Y between 0.1% and 0.7% by weight; Co between 21% and 23% by weight, Cr between 16% and 18% by weight, Al between 12% and 13% by weight, Y between 0.5% and 0.7% by weight, Si between 0.3% and 0.5% by weight, Hf between 0.2% and 0.3% by weight; Co between 11% and 13% by weight, Cr between 20% and 22% by weight, Al between 10.5% and 11.5% by weight, Y between 0.3% and 0.5% by weight, Re between 1.5% and 2.5% by weight; Co between 24% and 26% by weight, Cr between 16% and 18% by weight, Al between 9.5% and 11% by weight, Y between 0.3% and 0.5% by weight, Re between 1% and 1.8% by weight; Co between 23% and 25% by weight, Cr between 16% and 18% by weight, Al between 9.5% and 11% by weight, Y between 0.3% and 0.5% by weight, Ir between 1.1% and 1.5% by weight, balance Ni;