PURPOSE: To extract noble metal by solvent without generating precipitation of other base metals by reducing sulfoxide existing in organic solvent to corresponding sulfide and utilizing said reduction.

CONSTITUTION: Thiol and chlorotrialkylsilane are added to sulfoxide contained in organic solvent and expressed by the formula R1S(=O)R2 (R1 and R2 are alkyl or aryl) to reduce to corresponding sulfide. Further, gold and Pd are extracted from aqueous solution acidified by hydrochloric acid containing gold and/or Pd using organic solvent. In the extraction, it is performed by adding sulfide to organic solvent, and further adding thiol and chlorotrialkylsilane while reducing sulfoxide generated by oxidation of sulfide to the aimed sulfide.