An ejector system controls the idle speed of an internal combustion engine by controlling an electric throttle valve system that adjusts the flow-rate of the intake air to be supplied to the internal combustion engine, and includes an ejector which generates a negative pressure of which the absolute value is larger than the absolute value of a negative pressure to be introduced from an intake manifold, a vacuum control valve which causes the ejector to operate or causes the ejector to stop operating, and an ECU that controls the vacuum switching valve. With the ejector system, even if the ejector is caused to operate or caused to stop operating, it is possible to appropriately suppress fluctuations in the idle speed, and appropriately obtain a negative pressure.