A stack package with improved heat radiation capability and a module having the stack package mounted thereon are provided in which the back surfaces of first and second chips are exposed through the bottom and top surfaces of the stack package, allowing improved heat radiation capability as well as reduced thickness of the stack package. A measuring part being flowed through by a fluid to be tested is rotatably supported in the hollow cylinder. That is, under first wiring, diffusion regions are only formed in parts opposed to diffusion regions formed under the second wiring and third wiring connected to a power supply terminal or a ground terminal, and a diffusion region is not formed in a central part in an X direction. The operational amplifier has a non-inversion input terminal, which receives a reference voltage. Lateral flanges on the first and second trays have mutually registering socket and detent members arranged for cooperative engagement when the second tray is installed within the first tray. A method for coating a calcium phosphate compound on a biotissue substrate by an alternate soaking method which is characterized in that, as the soaking solutions, there are used a solution containing a water-soluble calcium salt and borate andor L-histidine and a phosphate solution.