A reaction container in which to mix a first chemical compound with a second chemical compound has a main body and a lid member formed oppositely on a top face side of the main body a flow channel on the top face of the main body and a labeling agent solidification section at an intermediate section of the flow channel to remove a solvent in a solution of the second chemical compound and solidify the second chemical compound. First and second chemical compound supply sections and a mixture discharge section are formed on the upstream and downstream sides of the labeling agent solidification section, respectively. The reactor is provided with a liquid sending unit to supply the first and second chemical compounds and reciprocally send a solution of the first chemical compound to an upper part of the second chemical compound solidified at the solidification section.
