Separator for a gaseous fluid adapted to separate liquid or solid pollutants entrained by a flow of said gaseous fluid, wherein said separator comprises a protective casing comprising an inlet port and an outlet port , an upper outlet disk and a lower discharge disk arranged inside the protective casing , wherein the upper outlet disk comprises a central through opening at the outlet port , wherein the lower discharge disk comprises a multiplicity of discharge ports , a first multiplicity of discharge ports which is hollowed inside the lower discharge disk and a second multiplicity of discharge ports hollowed on an annular edge of the lower discharge disk , a separator device arranged inside the protective casing between the upper outlet disk and the lower discharge disk , wherein the upper outlet disk is separated by an upper space from the separator device , wherein the inlet port is hollowed in a vertical wall of the protective casing and is adapted to let the flow of gaseous fluid pass into the upper space , wherein said separator device comprises vertical walls wound around a vertical longitudinal geometric axis (L) leaving in its inside a central longitudinal space and so as to form at least one spiral comprising a multiplicity of turns spaced from each other by a predefined pitch, wherein said at least one spiral forms a conduit comprising a rectangular longitudinal section in which a minor side (P) of the longitudinal section of the conduit is a transverse distance between two of the vertical walls which are adjacent and a longer side (H) of the longitudinal section of the conduit is a height of the vertical walls of the separator device . a protective casing comprising an inlet port and an outlet port , an upper outlet disk and a lower discharge disk arranged inside the protective casing , wherein the upper outlet disk comprises a central through opening at the outlet port , wherein the lower discharge disk comprises a multiplicity of discharge ports , a first multiplicity of discharge ports which is hollowed inside the lower discharge disk and a second multiplicity of discharge ports hollowed on an annular edge of the lower discharge disk , a separator device arranged inside the protective casing between the upper outlet disk and the lower discharge disk , wherein the upper outlet disk is separated by an upper space from the separator device , wherein the inlet port is hollowed in a vertical wall of the protective casing and is adapted to let the flow of gaseous fluid pass into the upper space , wherein said separator device comprises vertical walls wound around a vertical longitudinal geometric axis (L) leaving in its inside a central longitudinal space and so as to form at least one spiral comprising a multiplicity of turns spaced from each other by a predefined pitch, wherein said at least one spiral forms a conduit comprising a rectangular longitudinal section in which a minor side (P) of the longitudinal section of the conduit is a transverse distance between two of the vertical walls which are adjacent and a longer side (H) of the longitudinal section of the conduit is a height of the vertical walls of the separator device . <EOS>