Thin film production method and organic el device production method

A thin film production method according to one embodiment includes: a coating film forming step of forming a coating film by discharging a coating liquid on a support from first to M-th line heads (M is 2 or larger and N or smaller) while allowing the support to pass through N line heads once; and a drying step of obtaining a thin film by drying the coating film. A thin film forming nozzle hole 28 of the m-th line head (m is 2 or larger and M or smaller) is arranged to be positioned between adjacent thin film forming nozzle holes in an (m−1)-th thin film forming nozzle hole array Qm-1. Every time the first line head discharges the coating liquid, the m-th line head applies the coating liquid onto the support at a predetermined delay time with respect to a discharge time of the first line head. The first to M-th line heads discharge the coating liquid from the film forming nozzle hole selected in accordance with a shape of a thin film formation region onto the support.