Thermal Barrier Coatings (TBCs) are essential technique for increasing gas temperature on the gas turbines, but evaluation method for Young's modulus of top-coating has not established until now. On the other hand, indentation hardness tests are useful to evaluate materials properties, not only hardness value but also Young's modulus, tensile strength, and so on. In addition, indentation hardness tests have a lot of advantages, compared with another material testing - its simplicity, swiftness, and it is able to experiment with various materials such as composite or coating materials. Therefore, indentation hardness tests are suitable to evaluate Young's modulus of top-coating. In this paper, indentation hardness tests with a truncated conical indenter were carried out to evaluate Young's modulus of top-coating. As the results, effectiveness of the indentation theory for a truncated conical indenter was demonstrated from 4.9 to 9.8 N of testing load. Furthermore, load dependency of calculated Young's modulus was discussed.