PURPOSE: To evaluate a protective film easily and rapidly by applying thermal stress to the protective film through a resin substrate without executing a sealing resin.

CONSTITUTION: A chip 7 to which a protective film 6 is executed is placed onto the top face 5a of a resin substrate 5 so that the protective film 6 is brought into contact with the resin substrate 5. Fixed pressure is applied uniformly onto the whole top face of the chip 7 by using a fixture 8. A rubber layer 9 is interposed between the chip 7 and the mixture 8 so that the chip 7 is not damaged at that time. A hot plate 1 is heated at a fixed temperature while maintaining the state in which the surfaces of the resin substrate 5 and the chip 7 are brought into contact firmly. The thermal stress of a resin is applied to the protective film 6 formed onto the surface of the chip 7 by expanding and contracting the resin substrate 5, and cracks and pinholes are generated in the protective film 6. The chip 7 is treated with chemicals, thus easily detecting a defect such as the pinholes in the protective film 6.