Bonding member and a manufacturing method thereof

A microchip plate made such that polymer substrates made, in particular, of a cycloolefin polymer (COP) or a cycloolefin copolymer (COC) can be appropriately bonded to each other and a process for producing the microchip plate are provided. A microchip plate (1) of an embodiment is constituted by a first substrate (2) and a second substrate (3), which are bonded to each other through an adhesive layer (5), wherein the first substrate (2) and the second substrate (3) are formed by a COP or a COC, and the adhesive layer (5) is formed of paraffin or naphthene or formed including paraffin or naphthene and at least any one of an adhesion auxiliary material, a polymer constituting each of the first substrate and the second substrate, and a macromonomer.