Patent ID: 8398937

Claim:
A microchannel for transporting a liquid, comprising: an inflow portion located on an upstream side in a direction of flow; a discharge portion located on a downstream side in the direction of flow; and an enlarged portion located between the inflow portion and the discharge portion and having a cross-sectional area larger than those of the inflow portion and the discharge portion; wherein the discharge portion includes a pair of discharge openings located opposite to each other with respect to the inflow portion as viewed in the direction of flow, wherein the discharge portion further includes a retaining portion that is connected to at least one of the discharge openings on the downstream side in the direction of flow and has a cross-sectional area larger than that of the discharge opening, wherein the retaining portion is provided with a swelling member that inhibits outflow of the liquid from the retaining portion to the downstream side by swelling upon absorbing the liquid.