There is provided a dispensing mechanism for a liquid to be dispensed that does not damage microspherical bodies such as an erythrocyte and a liposome in the liquid to be dispensed when the liquid to be dispensed such as a sample and test liquid is sucked/discharged with a pipette. When a liquid to be dispensed of a sample or a test liquid being an object to be measured includes a microspherical body, and the microspherical body is one with such property that it may be damaged when being contacted with a liquid having an osmotic pressure different from that of the liquid in the microspherical body, the damage of the microspherical body is prevented by sequentially sucking a gas, a solution exhibiting an osmotic pressure that does not damage the microspherical body in the liquid to be dispensed and not having a bad effect on the measurement, the gas, and the liquid to be dispensed in a pipette the inside of which is filled with a liquid, because the pipette inside wall is substituted with the solution having an osmotic pressure that does not damage the microspherical body.