Disclosed are a pretreatment device and a mass spectroscope using same both enabling high-efficiency separation/refinement of a substance to be measured about multiple items through a series of solid-phase extraction steps with a small number of consumables used. An organic solvent is added to a solid phase (3) in position A of a cartridge transfer means (1), the organic solvent is passed through the solid phase (3) by means of a pressure load unit (7) in position B, an aqueous solvent is added to the solid phase (3) in position C, and the aqueous solvent is passed through the solid phase (3) in position D by means of the pressure load unit (7). The transfer means (1) rotates from position D to position A, a reagent and a sample are added to the solid phase (3), the sample is held by the solid phase (3) by means of the pressure load unit (7) in position B, an aqueous solvent is added to the solid phase in position C, and the solid phase cleaned with the aqueous solvent by means of the pressure load unit (7) in position D. The transfer means (1) rotates from position D to position A, an organic solvent is added to the solid phase (3), and the substance to be measured is eluted by a pressure load in position B and received in a container (5).