The present invention relates to a liquid channel device capable of easily opening the liquid channel from the closed mode, including a base plate in which a liquid channel, through which a liquid containing at least one of a sample and a reagent, flows, and a metering chamber for holding the liquid, are formed to at least one side thereof, the metering chamber has a liquid transport section for transporting the liquid inside the chamber downstream, and this liquid transport section is operated by means of external pressing on a cover plate in the area opposite the metering chamber.