A new type of flow sensor called profiled chamber flow sensor (PCF) was designed to overcome the default of existed volumetric flow sensor, including their complexity in structures and instability in measurement accuracy. The vital parts of PCF was a shell with characterized inner profiled chamber and a rotor with a pair of cross combined sliding plates. The inner profiled chamber had two quarter circular surfaces with different radius and two quarter noncircular surfaces, matching with the rotor and control the moves of cross combined sliding plates. By embedded elastic units, the cross sliding plates can compensate its end wear loss and avoid block caused by small particles in fluid, thus the persistence of measurement precision and a better reliability will achieve. PCF can be designed to work unidirectionally and bidirectionally through a little adjustment on inner profiled chamber. The structure of PCF is very simple, based on which pumps and prime movers with metering function of flow rate can be developed.