PURPOSE: To save labor eliminating constant monitoring with a warning given by calculating the initial capacity of reagents from several different reagent containers, the quantity per one distribution, the frequency of distributions per hour and the quantity of residual reagent from the operation time beginning with the reaction start time in an automatic analyzer.

CONSTITUTION: Reagents are distributed into a number of reaction tubes 2 from a plurality of reagent bottles 5 with respective pumps 6 in a reaction line 1 on which the reaction tubes 2 are arranged along a endless drive belt at an equal pitch and a photometric analysis or the like is done. Prior to this, a CPU 9 memorizes the initial capacity of respective reagent bottles a1, a2...an, the quantity per one distribution and the frequence of distribution per hour. A drive section 7 of a line 1 is operated with the action of a start switch at an input section 8 and the quantity of residual reagents in the reagent bottles a1...an is calculated from the passage time after the operation start time to determine the continuously measurable time whereby a warning is generated at an output section 10 by a display, a voice or the like. This can reduce the burden on an inspection engineer to allow a quicker preparation for measurement thereby enabling efficient operation of the equipment.