A rack collecting unit usable in a first sample processing apparatus and a second sample processing apparatus, wherein the first sample processing apparatus transports a sample rack (L) sent out from a rack setting unit to a rack collecting unit through a sample processing unit using a first transport path for transporting the sample rack in a first direction, and the second sample processing apparatus transports the sample rack (L) sent out from the rack setting unit to a sample processing unit using a first transport path for transporting the sample rack (L) in the first direction and thereafter transports the sample rack (L) to the rack collecting unit using a second transport path for transporting the sample rack (L) in a second direction opposite to the first direction, the rack collecting unit comprising: a storing section for storing therein the sample rack (L); characterised in that : the rack collecting unit further comprises: a third transport path connectable to the first transport path and capable of transporting the sample rack (L) in the first direction; a fourth transport path connectable to the second transport path and capable of transporting the sample rack (L) in the second direction; and a transferring section for transferring the sample rack (L) carried onto the third transport path or the fourth transport path to the storing section , in that : the third transport path and the fourth transport path are arranged in parallel with each other, and in that : the transferring section transfers the sample rack (L) in a direction orthogonal to the transport directions of the sample rack (L) transported by the third transport path and the fourth transport path . a storing section for storing therein the sample rack (L); characterised in that : the rack collecting unit further comprises: a third transport path connectable to the first transport path and capable of transporting the sample rack (L) in the first direction; a fourth transport path connectable to the second transport path and capable of transporting the sample rack (L) in the second direction; and a transferring section for transferring the sample rack (L) carried onto the third transport path or the fourth transport path to the storing section , in that : the third transport path and the fourth transport path are arranged in parallel with each other, and in that : the transferring section transfers the sample rack (L) in a direction orthogonal to the transport directions of the sample rack (L) transported by the third transport path and the fourth transport path . a third transport path connectable to the first transport path and capable of transporting the sample rack (L) in the first direction; a fourth transport path connectable to the second transport path and capable of transporting the sample rack (L) in the second direction; and a transferring section for transferring the sample rack (L) carried onto the third transport path or the fourth transport path to the storing section , in that : the third transport path and the fourth transport path are arranged in parallel with each other, and in that : the transferring section transfers the sample rack (L) in a direction orthogonal to the transport directions of the sample rack (L) transported by the third transport path and the fourth transport path . <EOS>