A method of detecting or quantifying a molecular target in a sample utilizing the molecular interaction between molecular targets, bead-bound probes, and support-bound probes. According to the invention, an adapter that is mounted on an intermediate container has a coded cylindrical jacket, into which coded parts that are positioned on the neck of a suitable supply container can be fitted. The cassette unit includes a casing which is the base member of the cassette unit; a movable cassette hopper on which a housed recording medium is to be placed; and a locking section that holds the attitude of the cassette hopper. Therefore, a clock enable signal and chip select signal do not enter an undefined state, and malfunctions that could otherwise occur are prevented.