An analyzing device having a microchannel structure includes a sample inlet and a guide section extending from the sample inlet toward an axial center. The analyzing device further includes a first cavity connected to the guide section and configured to measure a certain amount of a sample liquid, and a receiving cavity located adjacent to the first cavity and receiving the sample liquid. The analyzing device further includes a liquid reservoir formed between the sample inlet and the guide section and temporarily holds the sample liquid before being suctioned into the guide section. The sample liquid temporarily held in the liquid reservoir is transferred from the liquid reservoir to the guide section and the first cavity by a capillary force and transferred to the receiving cavity by a centrifugal force caused by rotating the analyzing device about the axial center.