An object of the invention is to provide a cassette and a measuring apparatus that can filter a sample for the optical measurement of an optically active substance and clean a sample flow channel by using a simple configuration. More specifically, the invention is directed to a cassette which includes a filter for filtering out a measurement interfering component from a sample, a container containing the filter, a cleaning liquid or cleaning agent for cleaning a sample flow channel, and a storage tank for storing the cleaning liquid or cleaning agent, and to a measuring apparatus having such a cassette.