Recently, many fork-lift trucks have come to use electronic governors. This is because gasoline engines need high power and engine speed control in order to improve the operation efficiency, and also need high fuel economy with engine speed control from the view point of environmental conservation. Based on these backgrounds, we developed an auto-tuning system for the PID controller of an electronic governor in order to make fine tuning and to reduce the period for controller development. We then designed a controller of the electronic governor using the H^∞ control theory that could consider the control performance and the robust stability at the same time that a controller was designed. We confirmed by experiments that the controller designed using the H^∞ control theory had good control performance and good robust stability.