In this paper, thermal stress analyses of all over the integrated circuit (IC), which is molded by resin and subjected to thermal load, are performed in detail. Two models of basic and practical constructions simulating the IC are analyzed. The analytical method is the special finite-element method proposed previously by the authors. In the analyses of basic constitutional models, the influence of the package thickness and the chip size to stress distributions of the IC are evaluated. Moreover, in the analysis of the practical IC model, the causes of failure of an actual IC are also discussed.