APPARATUS HAVING FUNCTION OF DILUTING SAMPLE AND METHOD FOR DILUTING SAMPLE

Contamination is prevented, and a sample and a diluent are more easily mixed together while the accuracy of the sample amount is maintained. An apparatus includes a sample preparation container preparing the sample, a diluent part storing the diluent for diluting the sample, and a control unit controlling operation of a sampling needle. The control unit includes a dilution operation part configured to add the diluent collected from the diluent part to the sample collected from a sample part with the sampling needle to dilute the sample in the container. The dilution operation part dispenses, with the sampling needle, the diluent into the container before dispensing of the sample, dispenses, with the sampling needle, the sample into the container into which the diluent has been dispensed, and thereafter dispenses, into the container, the diluent sucked with the sampling needle before suction of the sample.