Abstract: An FDG synthesizer, which comprises: a labeling reaction resin column comprising a column filled with a polymer-supported phase-transfer catalyst resin for trapping an ?.sup.18 F! fluoride ion contained in a target water, and performing a labeling reaction between the thus trapped ?.sup.18 F! fluoride ion and triflate, on the one hand, and a hydrolysis reaction vessel for receiving a reaction intermediate product obtained from the labeling reaction, and performing a hydrolysis reaction by adding a strong acidic aqueous solution or a strong alkaline aqueous solution thereto, on the other hand. The above-mentioned hydrolysis reaction vessel may be replaced with a cation-exchange resin column having a heating device and a flow rate control device of the reaction intermediate product.