An apparatus for analyzing liquid samples packed in tubes (6) closed with a top (7) capable of being perforated, includes a support (4) for the tubes and a unit (8) for sampling an aliquot from each tube and delivering it into a receptacle for treatment and/or analysis, the unit (8) including a hollow needle (45) connected to a suction/delivery device and vertically mobile; the support (4) has a circular tray provided with several tube-holders (5) on its periphery and capable of rotating about a vertical axis to bring a position successively and selectively the tubes (6) borne by the tube-holders (5) in line with the unit (8); each tube-holder (5) is connected to the tray (4) through a linkage (31) with two degrees of freedom.