The invention provides an automatic analyzing device and reagent house thereof. Wherein, a holding unit pivotally holds a plurality of reagent bottles which store reagents. A reagent case houses the holding unit and has an edge higher than at least the housed holding unit. The reagent cover is a cover for closing the reagent case. A cooling unit is mounted on one outer surface of the reagent caseand cools air in the reagent case closed by the reagent cover through one outer surface. A circulating unit is mounted on the holding portion and circulates the cooled air in the reagent case closed by the reagent cover.