Provided is a membrane carrier for a liquid sample test kit (3) that detects a substance to be detected in a liquid sample, the liquid sample test kit including at least one flow path (2) capable of transporting the liquid sample, in which a microstructure that causes a capillary action for transporting the liquid sample is provided on a bottom surface of the flow path (2), and a level difference at which a height level of the bottom surface changes, is provided in the flow path (2). The membrane carrier preferably has a detection zone for detecting a substance to be detected in the liquid sample.