This invention relates to a sulfonium salt, including its manufacturing method, which is effectively used as a photoacid initiator or radical photoinitiator during polymerization and a photoacid generator, leaving the protection groups of organic compounds, especially as an useful photoacid generator of the chemically amplified photoresist employed in semiconductor materials. Since the sulfonium salt of this invention, so prepared via one-step reaction between sulfoxide compound and aromatic compound in the presence of perfluoroalkanesulfonic anhydride, has the advantages in that by overcoming some shortcomings of the prior art to prepare the sulfonium salt via two steps using Grinard reagent, this invention may provide a novel sulfonium salt with higher yield which cannot be achieved in the prior art and also to prepare even any conventional sulfonium salt having better yield.