In conventional specimen-container loading/storing units, the number of types of specimen trays to be set in such a unit is preset to only one or two. If the number of types is changed, a hardware change is involved, for example. Accordingly, it is difficult to combine specimen trays at random to be flexibly set and used. Therefore, specimen trays cannot be selected appropriately for the number ofspecimen containers to be handled, which varies depending on a request or a specimen type, and thus, efficient operation of specimen-container loading/storing units is disturbed. In view of the aboveproblem, the present invention is characterized by comprising: a plurality of types of specimen trays that have different sizes and that each include a plurality of specimen-container holding units configured to hold specimen containers; a specimen-container transfer mechanism that transfers the specimen containers between a conveyance line and the specimen trays; and a specimen-tray setting uniton which the plurality of types of specimen trays can be set.