To provide a pretreatment column manufacturable with an easy method and capable of easily performing the analysis of an organic halogen compound, and an easy pretreatment method for the analysis of the organic halogen compound in a sample by use of the pretreatment column.

A silica gel layer of 0.25-3 g and a sulfuric silica gel layer of 0.5-6 g, and a silica gel layer of 0.5-3 g are provided on a column having an inside diameter of 0.7-1.5 cm from the sample injecting side. The organic halogen compound in the sample containing the organic halogen compound is extracted with an organic solvent, and the extract is decomposed with an alkali, and the extract after alkali decomposition is passed through the column and treated.