A pre-analysis treatment device usable for an amino acid, organic acid, and glucide includes an ion-exchange unit configured to load a test sample on a solid-phase cartridge S having a strong ion-exchange resin phase, to allow the strong ion-exchange resin phase to adsorb a predetermined organic compound, then supply a dehydration solvent to dehydrate the strong ion-exchange resin phase, and a derivatization unit configured to feed a predetermined amount of the derivatization reagent to the dehydrated strong ion-exchange resin phase to allow the derivatization reagent to retain for a predetermined time period, thereby trimethylsilylating the organic compound adsorbed on the strong ion-exchange resin phase, and simultaneously desorbing the trimethylsilylated organic compound from the strong ion-exchange resin phase, and then supply a push-out solvent to push the trimethylsilylated organic compound desorbed, out of the solid-phase cartridge S. The device enables at least one organic compound selected from amino acids, organic acids and glucides contained in a test sample to be derivatized and collected easily in a short period of time, and automation of the pre-analysis treatment.