We present a formula which can be used to analyze the anisotropic and apparent Faraday effect occurring in a material having an optically anisotropic property. By using the formula the real Faraday parameter can be obtained. For example, we have used the formula to study the anisotropic Faraday effect of a single‐crystal Cd0.55Mn0.45Te measured with the spectroscopic ellipsometer and rotating‐analyzer‐type Kerr apparatus. The calculated data were in good agreement with the experimental results. ©1995 American Institute of Physics.