PURPOSE: To form a thin resin layer film which has high crack resistance on the wiring pattern of a TAB lead type semiconductor device.

CONSTITUTION: High viscosity resin liquid is applied on a semiconductor pellet 1 under the condition that the rear plane of the pellet is turned over and a space between the window of a frame-shaped film 2 and the rear plane edge of the semiconductor pellet 1 is sealed by high viscosity resin 5A. Prebaking is performed, the high viscosity resin 5A is semisolidified and low-viscosity resin liquid is applied under the condition that the plane for forming a wiring pattern 7 is faced up. The inner lead part 3A and the wiring pattern 7 are coated with the low viscosity resin 5B. Secondary baking is performed for the intermediate body structure of the TAB lead type semiconductor device 8 and the wiring pattern 7 is coated with a thin layer film of the resin 5B.