As a flow rate control apparatus to which this invention is directed, in Patent Literature 1, there is proposed an apparatus including a body in which a required fluid passage is formed, a control valve, a sensor and a selector valve attached to the body, a first orifice disposed at an outlet passage from the control valve, a second orifice disposed at an outlet passage from the selector valve, and a control unit. The flow rate is controlled at the first orifice when the selector valve is closed, and the flow rate is controlled at the second orifice when the selector valve is opened (range changeable-type flow rate control apparatus).    Patent Literature 1: Japanese Patent Application Laid-Open No.