According to a flexible light-emitting device production method of the present disclosure, after an intermediate region (30i) and a flexible substrate region (30d) of a plastic film (30) of a multilayer stack (100) are divided, the interface between the flexible substrate region (30d) and a glass base (10) is irradiated with lift-off light. The multilayer stack (100) is separated into the first portion (110) and the second portion (120) while the multilayer stack (100) is kept in contact with the stage (210). The first portion (110) includes a plurality of light-emitting devices (1000) which are in contact with the stage (210). The light-emitting devices (1000) include a plurality of functional layer regions (20) and the flexible substrate region (30d). The second portion (120) includes the glass base (10) and the intermediate region (30i). The step of irradiating with the lift-off light includes forming the lift-off light from a plurality of arrayed light sources such that the irradiation intensity of the lift-off light for at least part of the interface between the intermediate region (30i) and the glass base (10) is lower than the irradiation intensity of the lift-off light for the interface between the flexible substrate region (30d) and the glass base (10).