An automatic analyzing apparatus comprising: a loading unit for loading racks (50, 51) on which a sample container containing a sample is mounted; a recovery unit for analyzed racks (50, 51); a transport line for transporting the racks (50, 51) upstream and downstream between the loading unit and the recovery unit; a sampling line for transporting the racks (50, 51) to a dispensing position where the sample is dispensed; a loading line for moving the racks (50, 51) from the transport line to the sampling line; a return line for moving the racks (50, 51) from the sampling line to the transport line, an analysis unit (4, 35) that is adapted to dispense the sample from the racks (50, 51) transported to the dispensing position and analyze the sample; and a control unit that is adapted to control the transport line and the sampling line, wherein the control unit is adapted to load the racks (50, 51) from the transport line onto the sampling line through the loading line, and after the dispensing at the dispensing position has been completed, the control unit is adapted to unload the racks (50, 51) from the sampling line onto the transport line through the return line under control, when a first rack is present in the sampling line and an analysis request for a second rack higher in the degree of urgency for analysis than the first rack is detected, the control unit is adapted to unload the first rack onto the transport line through the return line, and allow the first rack to stand by at a rack standby position under control, and the control unit is adapted to load the second rack from the transport line onto the sampling line through the loading line and transport the second rack to the dispensing position while the first rack is allowed to stand by, wherein the loading line is different from the return line, and characterised in that the rack standby position (302a, 304) is on the transport line between the loading line and the return line, and in that at the rack standby position there is no driving mechanism other than the driving mechanism for transporting the racks (50, 51) upstream and downstream. a loading unit for loading racks (50, 51) on which a sample container containing a sample is mounted; a recovery unit for analyzed racks (50, 51); a transport line for transporting the racks (50, 51) upstream and downstream between the loading unit and the recovery unit; a sampling line for transporting the racks (50, 51) to a dispensing position where the sample is dispensed; a loading line for moving the racks (50, 51) from the transport line to the sampling line; a return line for moving the racks (50, 51) from the sampling line to the transport line, an analysis unit (4, 35) that is adapted to dispense the sample from the racks (50, 51) transported to the dispensing position and analyze the sample; and a control unit that is adapted to control the transport line and the sampling line, wherein the control unit is adapted to load the racks (50, 51) from the transport line onto the sampling line through the loading line, and after the dispensing at the dispensing position has been completed, the control unit is adapted to unload the racks (50, 51) from the sampling line onto the transport line through the return line under control, when a first rack is present in the sampling line and an analysis request for a second rack higher in the degree of urgency for analysis than the first rack is detected, the control unit is adapted to unload the first rack onto the transport line through the return line, and allow the first rack to stand by at a rack standby position under control, and the control unit is adapted to load the second rack from the transport line onto the sampling line through the loading line and transport the second rack to the dispensing position while the first rack is allowed to stand by, wherein the loading line is different from the return line, and characterised in that the rack standby position (302a, 304) is on the transport line between the loading line and the return line, and in that at the rack standby position there is no driving mechanism other than the driving mechanism for transporting the racks (50, 51) upstream and downstream.