NOVELTY - The method involves providing a support substrate (100). A conductive layer (102) is coated on one surface of the support substrate. A plastic substrate (200) is formed on other surface of the support substrate. Multiple thin-film transistors (TFTs) are formed on the plastic substrate. An electronic device electrically connected to one of the TFTs is formed. The plastic substrate is separated from the conductive layer by generating Joule-heating by applying an electric field to the conductive layer. A sacrificial layer is formed on the support substrate before forming the plastic substrate.    USE - Method for fabricating an electronic device such as an organic LED, LCD, solar cell, electrophoretic-ink paper, programmed data processor (PDP), surface-conduction electron-emitter display (SED) and field emission display (FED) (all claimed).    ADVANTAGE - The method enables controlling a degree of separation according to the shape and thickness of the conductive layer, so that the separation time is shorter than that when the separation is performed using laser, thus providing easy fabrication of a large-area device, and improving fabrication yield. The method enables forming the insulative substrate on the conductive layer in the Joule-heating, thus preventing the occurrence of an arc. The method enables applies single-level energy not to have a continuous distribution when Joule-heating is performed by applying the electric field, so that the time taken to perform the Joule-heating is shorter than that in another separation process, thus avoiding conducting the heat generated in a separation process, and hence separating the flexible device reliably from the support substrate without deformation of the support substrate or degradation of the electronic device.    DESCRIPTION OF DRAWING(S) - The drawing shows a sectional view of an electronic device.    Support substrate (100)    Conductive layer (102)    Plastic substrate (200)    Passivation layer (202)    Insulating layer (210)