Patent ID: 8802008

Claim:
An automatic analyzer comprising: a plurality of sample containers each containing a sample; a plurality of reagent containers each containing a reagent; a plurality of reaction Cells into which the samples and the reagents are to be injected; a sample dispensing mechanism comprising a sample dispensing nozzle and dispensing the samples in the sample containers into the reaction Cells; a reagent dispensing mechanism comprising a reagent dispensing nozzle and dispensing the reagents in the reagent containers into the reaction Cells, and electrostatic capacitance measuring means for measuring electrostatic capacitance between the sample dispensing nozzle and the reaction Cell, wherein the sample dispensing nozzle has a nozzle main body made of metal, and a silicon oxide layer on an outer surface of the nozzle main body, and a silicon derivative having polyethylene glycol, represented by the following general formula: Si—R 1 —(OCH 2 CH 2 ) n —O—R 2 (n is a positive integer of 2 or more, R 1 is a hydrocarbon group, and R 2 is H or CH 3 ) is chemisorbed on the silicon oxide layer, and the electrostatic capacitance measuring means measures the electrostatic capacitance via the silicon oxide layer and the silicon derivative.