To provide methods for manufacturing a thin-film device, an active matrix substrate, and an electrooptical device such that the thin-film device such as an organic functional element is not damaged when peeled off from a substrate after being formed on the substrate, and can be handled as an independent body when peeled and further can be integrated with the other substrate after being peeled, and the thin-film device, the active matrix substrate, and the electrooptical device obtained by those methods.

A method includes a stage S1 of forming a separate film on a 1st base material, a stage S2 of forming a thin-film device on the separate film, a stage S3 of forming a protection film on the thin-film device, and a stage S5 of separating the 1st base material from the thin-film device. Contacting strength between the 1st base material and the separate film is made partially different in the stage S1, and the method includes a stage S4 of removing a part where the contacting strength between the 1st base material and the separate film is high is provided before the stage S5.