A reagent container used in an automatic analysis apparatus capable of preventing reagent in the reagent container from spattering out of the reagent container even when the reagent container with large capacity is rotated at a high speed and an automatic analysis apparatus using the reagent container are provided. A reagent container 12 for an automatic analysis apparatus has a first opening 27 used for sucking reagent and a second opening 28 used for the filling of the reagent. The second opening 28 is provided with an attachable/detachable lid 29. The lid 29 is provided with an air vent 33, a first shield plate 30 and a second shield plate 31 for preventing spattering of the reagent through the air vent 33 due to a wave motion of the reagent.