An electronic component mounting apparatus which employs a first air feed device connected to an air passage at one end part of a spline shaft, and a second air feed device connected to the air passage in the vicinity of the other end of the spline shaft. The first and second air feeds function to supply air to the air passage to return an interior thereof to atmospheric pressure. The time required to return the vacuum pressure in the air passage to atmospheric pressure can be shortened by the use of the two separate air feeds.