A connection device for connecting to a plurality of fluid containers that have openings, and a sample analyzer body for analyzing samples using reagent, is disclosed, which comprises: a plurality of tubular members for passing liquid, the plurality of tubular members being inserted in the fluid containers through the openings of the plurality of fluid containers; a holding member to hold the plurality of tubular members; and a plurality of cover members to be fitted to the opening of the fluid container, wherein the plurality of cover members are arranged in a predetermined positional relationship on the holding member side of the plurality of tubular members; configured with a continuously decreasing cross sectional area toward the fluid container side; and the shape of the cross section of the cover member is substantially the same as the shape of the corresponding opening of the fluid container.