In this paper, the high frequency induction heating apparatus developed by the authors is used to analyze thermal stresses produced in the disk with star-shaped hole rounded the tip. The photoelastic experiment for the epoxy disk models perforated various star-shaped holes is performed in steady-state temperature distribution under heating conditions of 50°C and 0°C on the inner and outer edges, respectively. Some of the experimental values are compared with the numerical values by means of finite element method.