A washing system for a gas turbine engine with an axial compressor, comprising: an inlet screen arranged to be positioned when in use at the air flow inlet of the axial compressor to protect the compressor from foreign object damage, the inlet screen comprising a supporting structure (10, 11, 12) and a filtering net fixed to the supporting structure (10, 11, 12), an arrangement of nozzles and manifolds (13, 17), said arrangement (13, 17, 18) being integrated in said supporting structure (10, 11, 12) and a washing liquid supply system connected to said arrangement (13, 17, 18); wherein the inlet screen comprises a base arranged to be positioned when in use at the air flow inlet of the axial compressor and a lateral surface developing away from the first base and having an axially symmetrical shape; and wherein the inlet screen has the shape of a cylindrical cup, and wherein the supporting structure (10, 11, 12) comprises: a first support ring disposed at the periphery of the cylinder cup base close to the air flow inlet of the axial compressor, a second support ring disposed at the periphery of the other cylinder cup base remote from the air flow inlet of the axial compressor, a set of L-shaped ribs, short segments of said ribs being parallel and spaced-apart joining said rings (10, 11) and long segments of said ribs being disposed radially in said second support ring and joined at its center. an inlet screen arranged to be positioned when in use at the air flow inlet of the axial compressor to protect the compressor from foreign object damage, the inlet screen comprising a supporting structure (10, 11, 12) and a filtering net fixed to the supporting structure (10, 11, 12), an arrangement of nozzles and manifolds (13, 17), said arrangement (13, 17, 18) being integrated in said supporting structure (10, 11, 12) and a washing liquid supply system connected to said arrangement (13, 17, 18); wherein the inlet screen comprises a base arranged to be positioned when in use at the air flow inlet of the axial compressor and a lateral surface developing away from the first base and having an axially symmetrical shape; and wherein the inlet screen has the shape of a cylindrical cup, and wherein the supporting structure (10, 11, 12) comprises: a first support ring disposed at the periphery of the cylinder cup base close to the air flow inlet of the axial compressor, a second support ring disposed at the periphery of the other cylinder cup base remote from the air flow inlet of the axial compressor, a set of L-shaped ribs, short segments of said ribs being parallel and spaced-apart joining said rings (10, 11) and long segments of said ribs being disposed radially in said second support ring and joined at its center. a first support ring disposed at the periphery of the cylinder cup base close to the air flow inlet of the axial compressor, a second support ring disposed at the periphery of the other cylinder cup base remote from the air flow inlet of the axial compressor, a set of L-shaped ribs, short segments of said ribs being parallel and spaced-apart joining said rings (10, 11) and long segments of said ribs being disposed radially in said second support ring and joined at its center.