Abstract: A chemical analyzer is disclosed in which a sample is supplied from a sample cup on a sample table to an array of reaction cups on a reaction table so that the reaction cups contain the same amount of sample, a reagent pipetting nozzle sucks an appropriate reagent solution from an array of reagent tanks and discharges the reagent solution into a corresponding reaction cup, the sample having reacted with the reagent solution is optically measured by a multi-wavelength photometer, a plurality of reagent tanks containing different reagent solutions are placed in a refrigerator with the openings of the reagent tanks being directed upward, the refrigerator is provided with a cover which has holes provided at positions corresponding to the openings of the reagent tanks, these holes are closed by a shutter except when the reagent pipetting nozzle is inserted into these holes, the array of reaction cups is immersed in constant-temperature-water contained in a reaction bath, the reaction bath is supplied with water wh