An automatic analysis device comprising: a reagent storage chamber that stores a reagent container containing a reagent; and a lid opening and closing device that includes a lid opening and closing member configured to be movable in a first direction parallel to a vertical direction and to be movable in a second direction perpendicular to the first direction, wherein the lid opening and closing member includes a first member and a second member that are integrated with each other, the first member opening a lid of the reagent container , and the second member closing the lid , the lid opening and closing member is configured to be movable between a first position and a second position, the first position being a position above the reagent container , the second position being a position that is moved down from the first position in the first direction, the lid opening and closing member is configured to be movable between the second position and a third position being a position that is moved from the second position in the second direction, in a case where the lid opening and closing member moves from the second position to the third position, the lid is opened by the first member , and in a case where the lid opening and closing member moves from the third position to the second position, the lid is closed by the second member , characterized in that the second position is a position where the lid opening and closing member is moved down from the first position in the first direction until a bottom surface of the lid opening and closing member comes into contact with the reagent container . a reagent storage chamber that stores a reagent container containing a reagent; and a lid opening and closing device that includes a lid opening and closing member configured to be movable in a first direction parallel to a vertical direction and to be movable in a second direction perpendicular to the first direction, wherein the lid opening and closing member includes a first member and a second member that are integrated with each other, the first member opening a lid of the reagent container , and the second member closing the lid , the lid opening and closing member is configured to be movable between a first position and a second position, the first position being a position above the reagent container , the second position being a position that is moved down from the first position in the first direction, the lid opening and closing member is configured to be movable between the second position and a third position being a position that is moved from the second position in the second direction, in a case where the lid opening and closing member moves from the second position to the third position, the lid is opened by the first member , and in a case where the lid opening and closing member moves from the third position to the second position, the lid is closed by the second member , characterized in that the second position is a position where the lid opening and closing member is moved down from the first position in the first direction until a bottom surface of the lid opening and closing member comes into contact with the reagent container . <EOS>