A fluid control apparatus is provided with a fluid control valve for controlling the flow volume of a fluid by changing an opening area of a flow channel; a flow volume measuring apparatus for measuring the flow volume of the fluid, converting the measured value of the flow volume into electric signals and outputting the signals; and a control section for outputting a command signal for controlling an opening area of the fluid control valve to the fluid control valve or to an apparatus which operates the fluid control valve, based on a deviation of the electric signal from a set flow volume outputted from the flow volume measuring apparatus.