Abstract: A semiconductor device manufacturing method according to the present invention includes a step of arranging a plurality of processing objects on a first tray and a second tray adjacent to the first tray, a plurality of application steps in which application of an application substance to the plurality of processing objects is repeated a certain number of times by emitting the application substance from an application device formed right above a contact position at which the first tray and the second tray contact each other, by swinging the application device along a first direction across the contact position, and by moving the first tray and the second tray in a second direction perpendicular to the first direction, and an interchange step of interchanging the first tray and the second tray in position without changing the directions of the first tray and the second tray corresponding to the second direction, the interchange step being executed at least one time among the plurality of application steps.