First and second racks each has fixed positions to hold sample tubes. First and second drawers slide into and out of the case, and that support the first and second racks, respectively. A tube set unit is provided in an area close to the first rack in the case. A tube transfer unit removes sample tubes from the first and second racks in the case and a controller that controls a transfer operation of the tube transfer unit. The first rack is supported by the first drawer such that the first rack leaves a transit location in the case behind the first drawer in the direction of the first drawer movement into the case. The controller controls the tube transfer unit to remove at least one sample tube from the second rack and transfers the tube to the tube set unit via a path traversing the transit location.