High-precision Proportional Control Valve has been newly developed, which is optimum for the production lines, plants, etc of air, gas, liquid, etc. The stepless control is realized, which is necessary to control the flow rate of gas and liquid. Standard input signal can be selected from 4 to 20mA in current as well as 0 to 10 V in voltage. Controller is equipped with initial setting support circuit, so that the initial setting is performed without any external input.