It is considered that there is some deep relationship between studies on the structured singular value and on robust D-stability analyses of systems with parametric uncertainties. Studies on the relationship, however, are very few in number. In this paper, we show an attempt to study one of the relationship. The attempt is to compute the real structured singular value μ by using the stability feeler, which is a tool for robust D-stability analysis of polytopic polynomials. A numerical example is provided to show that an upper bound and a lower bound of μ are successfully obtained by using the stability feeler. We also compare the result to those derived by conventional methods. Moreover, this paper discuss the computational complexity of the proposed method.