An electronic component mounting machine is provided with a film thickness gage. The film thickness gage is provided with measurement sections. The mounting head moves to a position above the storage section and lowers the film thickness gage to cause the film thickness gage to come into contact with the flux film. In the film thickness gage, the measurement sections form measurement marks corresponding to the film thickness in the flux film. The electronic component mounting machine images the measurement marks using a mark camera, and determines the film thickness of the flux film which is actually formed based on imaging data.