PURPOSE: To provide the method and instrument for measuring bodily fluid components, such as sweat and exudation liquid, drawn from the skin, etc., which can measure the bodily fluid component with a minute amt. and can continuously monitor these components.

CONSTITUTION: A bodily fluid component drawing cell 1 is brought into tight contact with the skin 3 and the bodily fluid 6 is drawn by suction from a reduced pressure suction port 4. A housing 8 is installed on the bodily fluid drawing route communicating with a suction pump 7 and a fixed delivery valve 9 is disposed therein. A through-hole 10 is formed in the fixed delivery valve 9 and is used commonly for a bodily fluid 6 storage chamber. The bodily fluid 6 determined at a constant rate is sent to a flow type measuring cell 13 by a liquid feed pump 12 when the through-hole 10 is turned by the control of a controller 11. The components are then measured by a sensor 14.