In a sample-processing system that includes one or more function modules and one or more buffer units each combined as a pair with one of the function modules, in case of device stoppage due to failure, since a number of sample racks are held in the buffers, resetting involves a huge amount of time for storage of the racks. In addition, if the system configuration includes a plurality of buffer units, the resetting time increases with the number of buffer units. Sample rack ID reading means is provided in each buffer unit and during resetting, IDs of the sample racks in the buffer unit are read in the buffer unit. The buffer unit then uses the read information to make an inquiry to a control unit as to transport destinations of each sample rack. After this, sample processing based on transport destination instructions from the control unit is restarted using the buffer unit as a restarting position.