[Problem] To accurately control the ejection of chemicals and increase the safety of the ejection of the chemicals in an agricultural machine for spraying the chemicals. [Solution] This system, which is for controlling the ejection of chemicals and is provided in an agricultural machine that has a chemical tank and a chemical ejection port and sprays chemicals, has a plurality of sensors and detects the discharge amount of the chemicals by means of the sensors. The sensors may be any among: pressure sensors for measuring the ejection pressure of the chemicals； pressure sensors provided in the vicinity of a pump and measuring the ejection pressure of the chemicals ejected downstream； pump sensors for measuring the rotation speed of a rotor inside the pump； and flow sensors for measuring the flow rate of the chemicals.
