Substrate processing device and dispensing head

A dispensing head (220) in a component mounting device (100) is provided with a valve mechanism (90) that can switch between the following states: a first switch state in which pressure is applied to an adhesive via a storage chamber (71) so as to dispense said adhesive from a dispensing opening (14a); a first switch state in which the adhesive is not dispensed; and a third switch state in which the dispensing opening (14a) is connected to the outside atmosphere via the storage chamber (71). When a control operation is inputted to a cylindrical gear (72) via a head holder, a switching unit (73) changes the state of the valve mechanism (90) on the basis of the inputted control operation. A clutch member for the head holder is used for both control operations performed on a vacuum head and control operations performed on the cylindrical gear (72) in the dispensing head (220). Said clutch member is capable of controlling a mechanism that axially rotates a vacuum nozzle on the vacuum head. The aforementioned cylindrical gear (72) is exposed on a surface that connects to the head holder when the dispensing head (220) is held by the head holder.