Abstract: A reaction chip includes: a first base which contains a metallic base and has a first surface; and a second base which contains a resin base and has a second surface, wherein the first surface and the second surface are joined so as to face each other; the first surface has a plurality of first recess portions and a groove portion located between the plurality of the first recess portions; the second surface has a plurality of second recess portions located corresponding to the plurality of the first recess portions; the plurality of the first recess portions and the plurality of the second recess portions are configured so as to form a plurality of reaction vessels; and the groove portion is configured so as to form a flow passage that communicates among the plurality of reaction vessels with each other.