PURPOSE: To realize a rapid and accurate measurement of viscosity by a capillary rheometer continuously or discontinuously measuring the viscosity of a liquid housed in a container.

CONSTITUTION: A fluid is supplied to a capillary by a metering pump, and the fluid is supplied to the metering pump by a supply pump and the inlet of the supply pump is formed so as to have the shape capable of being attached to the fluid sample collecting port of a container and the outlet of the supply pump is formed so as to return the sample fluid not guided within the capillary to a liquid or the container. The emitting end of the capillary is connected to the pump and can suck the fluid by the capillary. The supply pump and the quantitative supply pump can be regulated mutually independently.