Fluid flow-passage device

A fluid flow-passage device in which a plurality of fluid flow-passages which extend in parallel to each other and through each of which a fluid is made to flow are formed, comprising:

• a body having a plurality of substrates laminated in a predetermined lamination direction;
• and
• a plurality of lids, each of which can be attached to and detached from the body,
• wherein each of the plurality of fluid flow-passages includes:
• a first fluid flow-passage formed between two substrates in contact with each other in the lamination direction out of the plurality of substrates;
• a second fluid flow-passage formed between two substrates in contact with each other in the lamination direction out of the plurality of substrates, disposed at a position in the lamination direction different from that of the first fluid flow-passage, and positioned on a downstream side with respect to the first fluid flow-passage in the direction in which the fluid flows;
• and
• a third fluid flow-passage, which connects a downstream end of the first fluid flow-passage and an upstream end of the second fluid flow-passage with each other in the lamination direction,
• wherein an upstream end and the downstream end of the first fluid flow-passage open at least one of side surfaces respectively belonging to each of the two substrates forming the first fluid flow-passage out of the plurality of substrates,
• wherein the upstream end and the downstream end of the second fluid flow-passage open at least one of side surfaces respectively belonging to each of the two substrates forming the second fluid flow-passage out of the plurality of substrates, and
• wherein the plurality of lids include:
• a first lid covering the upstream end of the first fluid flow-passage in a state in which the first lid is attached to the body;
• and
• a second lid covering the downstream end of the first fluid flow-passage and the upstream end of the second fluid flow-passage in a state in which the second lid is attached to the body.