According to a flexible OLED device production method of the present disclosure, after an intermediate region (30i) and flexible substrate regions (30d) of a plastic film (30) of a multilayer stack (100) are divided from one another, the interface between the flexible substrate regions (30d) and a glass base (10) is irradiated with laser light. The multilayer stack (100) is separated into a first portion (110) and a second portion (120) while the multilayer stack (100) is in contact with a stage (212). The first portion (110) includes a plurality of OLED devices (1000) which are in contact with the stage (212). The OLED devices (1000) include a plurality of functional layer regions (20) and the flexible substrate regions (30d). The second portion (120) includes the glass base (10) and the intermediate region (30i). The stage (212) has ejection holes in a region which is to face the intermediate region (30i), from which a fluid is ejected in the separation step.