The flow rate control unit 1 is comprised with each of the flow rate control devices 11 connected to (juxtaposedly mounted on) the manifold 2 by the joint 91 interposed between each of the flow rate control devices 11 and the manifold 2. Each of the flow rate control devices 11 can be attached to or detached from the manifold 2 by manually operating (attaching/detaching) the clip 93 without using a tool. Because there is no need to secure space to insert a tool between the adjacent flow rate control devices 11, the mounting pitch between the adjacent flow rate control devices 11 (joints 91) can be reduced to the minimum, allowing miniaturization of the flow rate control unit 1.