An automated analyzer includes pipetting means for discharging a sample and reagent into an empty reaction vessel without causing contact to occur between the leading end of a sample probe and the bottom of the reaction vessel. The sample probe is inserted into the reaction vessel and then stopped when a bottom end of an outer pipe of the sample probe comes in contact with the top edge of the reaction vessel to maintain a fixed gap between the leading end of an inner pipe of the sample probe and the bottom of the reaction vessel. Further, an insulating material is disposed between the inner and outer pipes of the sample probe.