A sample conveying system including: sample container holders, each of which being capable of holding a sample container, wherein the sample container holders are provided with, as identifiers, information recording media equipped with non-volatile semiconductor memories respectively, a conveying line for conveying the sample container holders to a sample processing unit and for returning the sample container holders finished with processes of the sample processing unit to an upstream side of the write unit, an unload unit for supplying the sample container holders to the conveying line, a write unit for storing a write count (n) representing the number of times information has been written to said information recording media to a write count storage mechanism of the semiconductor memories, a write count comparison mechanism for comparing the write count (n) stored in the write count storage mechanism with a predetermined maximum value (x), and a conveying line control mechanism, characterised in that the sample conveying system further includes a bypass line for bypassing the sample container holder to the upstream side of the conveying line at a shorter time in comparison with the case where the sample container holder is returned through the conveying line, and the conveying line control mechanism is adapted to perform such control that when the write count comparison mechanism determines that, for a sample container holder provided with the semiconductor memory as the identifier, the write count (n) of the semiconductor memory is larger than the predetermined maximum value (x) or does not fall within a numeric range having an average value (y) of write counts (n) at its centre, writing to the semiconductor memory is skipped and a skip conveyance is performed by returning the sample container holder to the upstream side of the write unit through the bypass line or the conveying line. sample container holders, each of which being capable of holding a sample container, wherein the sample container holders are provided with, as identifiers, information recording media equipped with non-volatile semiconductor memories respectively, a conveying line for conveying the sample container holders to a sample processing unit and for returning the sample container holders finished with processes of the sample processing unit to an upstream side of the write unit, an unload unit for supplying the sample container holders to the conveying line, a write unit for storing a write count (n) representing the number of times information has been written to said information recording media to a write count storage mechanism of the semiconductor memories, a write count comparison mechanism for comparing the write count (n) stored in the write count storage mechanism with a predetermined maximum value (x), and a conveying line control mechanism, characterised in that the sample conveying system further includes a bypass line for bypassing the sample container holder to the upstream side of the conveying line at a shorter time in comparison with the case where the sample container holder is returned through the conveying line, and the conveying line control mechanism is adapted to perform such control that when the write count comparison mechanism determines that, for a sample container holder provided with the semiconductor memory as the identifier, the write count (n) of the semiconductor memory is larger than the predetermined maximum value (x) or does not fall within a numeric range having an average value (y) of write counts (n) at its centre, writing to the semiconductor memory is skipped and a skip conveyance is performed by returning the sample container holder to the upstream side of the write unit through the bypass line or the conveying line.