To provide a method and an apparatus in which an organic sulfur compound in liquid oil is continuously, safely and effectively oxidation recovered by using an oxidizing agent containing hydrogen peroxide and the liquid oil is refined.

A method for recovering an organic sulfur compound in liquid oil and refined liquid oil comprises providing an amount of an oxidizing agent in a reactor 1 being at least 300 times of a necessary amount to oxidize the organic sulfur compound in the liquid oil to a corresponding sulfone compound, introducing the liquid oil in fine particles grinded in a fine grinding syringe 4 into the oxidizing agent in the reactor 1, rising the fine particles of the liquid oil while catalytic reacting the particles with the oxidizing agent in high speed flowing by an agitator 20 in the reactor 1, oxidizing the organic sulfur compound to become a reaction solution, cooling the reaction solution at a heat exchanger 26, separating the liquid oil containing an oxidized organic sulfur compound from the oxidizing agent by a separator 5, and then separating the oxidized organic sulfur compound and refined oil from the liquid oil and recovering as the organic sulfur compound and the refined oil.