To enhance the flatness of the adhesive surface of the light pervious plate inserted in a metal plate, in a microplate having the light pervious plate bonded thereto.

A first gate for allowing a first resin for forming a well part 4 to flow in the cavity of a mold and a second gate for allowing a second resin for forming an outer frame part 10 to flow in the cavity are arranged to the cavity so as to be opposed to the surfaces of aluminum plates 6 on mutually different surface sides. The aluminum plates 6 are arranged in the respective cavities of the forming part of the well part 4 and the forming parts of the intermediate parts of respective sides in the square shape of the outer frame part 10 and the first and second resins are allowed to flow in the cavities from the first and second gates to form the well part 4 and the outer frame part 10 to form the resin plate 3.