A method for extracting a component in a sample in solid phase in order to provide means effective for pretreating a sample being introduced to a chromatograph. The method comprises a step for providing a needle at the forward end of a syringe having a tube and a plunger slidable in the tube, forming a porous body of so-called monolithic structure in the needle at least over a proper length and the entire diameter and then inserting the needle into a sample, a step for passing the sample through the needle and holding a target component in the porous body, and a step for separating the target component from the interior of the porous body.