A measuring and controlling system is provided which has a control function as well as a measurement function to perform the measurement and control of fluid amounts such as the flow rate, pressure, liquid level, weight and so on by itself in the same field. A pressure receiving unit is directly mounted on a pipe or a container, in which a fluid under measurement exists, in order to detect the temperature, differential pressure and static pressure of the fluid under measurement independently of each other. Means for storing the characteristic of fluids under measurement is provided such that the mass flow rate, weight and liquid level can be calculated. By providing the transmitter with the measurement and control functions, the measurement and control of fluid amounts such as flow rate, pressure, liquid level, weight and so on can be performed in a closed form, thereby making it possible to simplify a correction procedure for the static pressure and temperature, improve the responsibility, and enhance the control performance of the whole plant. Also, a measuring and controlling system can be realized which reduces a wiring amount for connecting with an upper level control unit.