A pre-analysis treatment device (1, 2) usable for an amino acid, organic acid, and glucide, the pre-analysis treatment device (1, 2) comprising a sample-storing unit for storing a test sample, a solid-phase cartridge having a strong ion-exchange resin phase that adsorbs at least one organic compound selected from amino acids, organic acids and glucides possibly contained in the test sample, a dehydration solvent-storing unit for storing a dehydration solvent that dehydrates the strong ion-exchange resin phase on which the test sample is loaded, a first nozzle used for at least one of discharging the dehydration solvent, withdrawing the test sample, and ejecting the test sample, a first feed pump for supplying the dehydration solvent and the test sample via the first nozzle to the solid-phase cartridge, a derivatization reagent-storing unit for storing a derivatization reagent that trimethylsilylates the organic compound adsorbed on the strong ion-exchange resin phase, a push-out solvent-storing unit for storing a non-ion-exchanging push-out solvent that pushes the trimethylsilylated organic compound out of the solid-phase cartridge, a second nozzle used for at least one of discharging the push-out solvent, withdrawing the derivatization reagent, and discharging the derivatization reagent, a second feed pump for supplying the derivatization reagent and the push-out solvent via the second nozzle to the solid-phase cartridge, an ion-exchange unit configured to (i) withdraw a prescribed amount of the test sample by the first feed pump in a state that an outlet side of the first nozzle is connected to the sample-storing unit, (ii) then feed the test sample withdrawn, with the dehydration solvent in a state that the outlet side of the first nozzle is connected to an inlet side of the solid-phase cartridge, (iii) load the test sample on the solid-phase cartridge to allow the strong ion-exchange resin phase to adsorb the organic compound, and (iv) then supply the dehydration solvent to dehydrate the strong ion-exchange resin phase, and a derivatization unit configured to (i) withdraw a prescribed amount of derivatization reagent by the second feed pump in a state that an outlet side of the second nozzle is connected to the derivatization reagent-storing unit, (ii) feed the prescribed amount of the derivatization reagent with the push-out solvent in a state that the outlet side of the second nozzle is connected to an inlet side of the solid-phase cartridge, (iii) suspend the feed of the push-out solvent for a particular time so as to retain the derivatization reagent, thereby trimethylsilylatingthe organic compound adsorbed on the strong ion-exchange resin phase in the ion-exchange unit, and simultaneously desorbing the trimethylsilylated organic compound from the strong ion-exchange resin phase, and (iv) then supply the push-out solvent to push the desorbed trimethylsilylated organic compound out of the solid-phase cartridge. (i) withdraw a prescribed amount of the test sample by the first feed pump in a state that an outlet side of the first nozzle is connected to the sample-storing unit, (ii) then feed the test sample withdrawn, with the dehydration solvent in a state that the outlet side of the first nozzle is connected to an inlet side of the solid-phase cartridge, (iii) load the test sample on the solid-phase cartridge to allow the strong ion-exchange resin phase to adsorb the organic compound, and (iv) then supply the dehydration solvent to dehydrate the strong ion-exchange resin phase, and (i) withdraw a prescribed amount of derivatization reagent by the second feed pump in a state that an outlet side of the second nozzle is connected to the derivatization reagent-storing unit, (ii) feed the prescribed amount of the derivatization reagent with the push-out solvent in a state that the outlet side of the second nozzle is connected to an inlet side of the solid-phase cartridge, (iii) suspend the feed of the push-out solvent for a particular time so as to retain the derivatization reagent, thereby trimethylsilylatingthe organic compound adsorbed on the strong ion-exchange resin phase in the ion-exchange unit, and simultaneously desorbing the trimethylsilylated organic compound from the strong ion-exchange resin phase, and (iv) then supply the push-out solvent to push the desorbed trimethylsilylated organic compound out of the solid-phase cartridge.