A method for extracting nucleic acid comprises: (a) putting a biological material in contact with a lysing solution to dissolve out nucleic acid; (b) adding a water-soluble organic solvent to an obtained solution of the dissolved nucleic acid, to prepare a lysate solution; (c) putting the lysate solution in contact with a solid material, to allow the nucleic acid to be adsorbed onto the solid material; (d) washing off impurities on the solid material, using a washing solution, wherein twice or more washing procedures are conducted, and a liquid face formed with a washing solution applied in at least one washing procedure other than the first washing procedure among the twice or more washing procedures is higher than a liquid face formed with a washing solution applied in the first washing procedure; and (e) desorbing the nucleic acid adsorbed onto the solid material, using a recovering solution.