A dent is formed on a side surface of a first substrate. A second substrate faces to the side surface of the first substrate. A third substrate is arranged so that the first and second substrates contact each other closely. A micro flow path and a micro chamber are formed between the first and second substrates. The micro flow path and the micro chamber communicate with each other and including an inlet and outlet respectively. A fifth substrate contains the first, second and third substrates. A fourth substrate fits in the fifth substrate. The first and second substrates are pressed against each other by thread fastening (pressing means) for the fourth and fifth substrates.