Automatic analyzer

The automatic analyzer comprising:

• the reaction disk with a plurality of the reaction vessels placed on a circumference of a circle, the reaction disk being configured to be rotated;
• a first dispensing unit that dispenses the liquid to the reaction vessel placed on the reaction disk;
• a second dispensing unit that dispenses the liquid to the reaction vessel placed on the reaction disk;
• the transport unit that loads the reaction vessel to the reaction disk;
• the spectrophotometer having the optical axis arranged so as to cross a circumference of a circle of the reaction disk;
• and
• the control unit,
• wherein:
• the control unit controls the reaction disk, the first dispensing unit, the second dispensing unit, and the transport unit in synchronization with the analyzer cycle;
• the sum total of the amount of rotation of the reaction disk in the analyzer cycle is set, the analyzer cycle includes a photometric rotation period in which the reaction disk is rotated at one turn or more, the first positioning rotation period and the second positioning rotation period in which the reaction disk is stopped at a position corresponding to the sum total at an end of the analyzer cycle,
• the first suspension period between the first positioning rotation period and the second positioning rotation period, and a second suspension period between the second positioning rotation period and the end of the analyzer cycle;
• the first dispensing unit, the second dispensing unit, and the transport unit access to the reaction vessel that has stopped at a set access position in the first suspension period or the second suspension period;
• and
• the sum total of an amount of rotation of the reaction disk in the analyzer cycle is determined such that ßM=αN±2 is satisfied where a number of the reaction vessels placeable on the reaction disk is N, the sum of the sum totals of amounts of rotation of two of the analyzer cycles that continue is M, and α and ß are constants.