To greatly increase the speed of an automatic electronic parts mounting apparatus equipped with an adsorption nozzle, and also certainly mount electronic parts on a printed-circuit board.

This mechanism is equipped with a first rod moving chamber 13 which is communicated with an air supply chamber 49 and also communicated with a positive pressure air supply line 58 through a positive pressure air supply opening 24, a second rod moving chamber 19 which is communicated with the air supply chamber 49 and also communicated with a negative pressure air supply line 57 through a negative pressure air supply opening 17, and valve rods 25, 26 which open/close the air supply opening by being respectively moved in the rod moving chamber 13, and which are connected to each other by a link member 28 having a rotary fulcrum 28a in its intermediate part. When one valve rod is moved so as to close the negative pressure air supply opening 17 or the positive pressure air supply opening 24, the other valve rod is moved in a direction oppose to the moving direction of the foregoing valve rod by the link member 28 so that the positive pressure air supply opening 24 or the negative pressure air supply opening 17 can be opened.