Patent ID: 8168444

Claim:
A substrate that is rotatable about a rotating axis and that has a flow path part including a chamber formed inside the substrate, wherein: an interior wall of the chamber, which is configured to generate no capillary force, comprises: a first inner face that has a plane intersecting with a centrifugal direction being a line running orthogonal to the rotating axis of the substrate from the rotating axis; and a second inner face that has a plane which is placed in a location farther from the rotating axis than the first inner face and which is intersecting with the centrifugal direction being a line running orthogonal to the rotating axis of the substrate from the rotating axis; wherein the first inner face has an area on which a droplet of liquid supplied is retained, and has an area that allows expansion of a contact area of the retained droplet by rotation of the substrate and communicates with the second inner face.