A bonded member which includes substrates constituted of a cycloolefin polymer (COP) or a cycloolefin copolymer (COC) and in which adequate bonding between the substrates is possible. Also provided is a process for producing the bonded member. A microchip plate (1) is provided which is characterized by comprising a first substrate (2), a second substrate (3), and an adhesive layer (5) through which the substrates have been bonded to each other. The plate (1) is further characterized in that the first substrate (2) and the second substrate (3) are formed from a COP or COC, and that the adhesive layer (5) comprises a paraffin or naphthene or comprises a paraffin or naphthene and at least any one of adhesion promoters and the polymers and macromonomers constituting the first substrate and second substrate.
