The purpose of this study is to examine the basic characteristics of the single layer type microwave absorber in X band. Samples were produced from Bi system (2223) superconductor powder and metallic powder and inserted into a wave guide system where the complex reflection intensity was measured (The short circuit method) by using the vector network analyzer. As the result, at the room temperature (300K), the reflection loss is apt to increase with increasing the content of the Bi system superconductor powder. Furthermore, the measured value of the reflection loss agreed with the value calculated from the complex permittivity εr* . At liquid nitrogen temperature (77K) where the superconductor powders are in the superconducting state, some differences occurred between the calculated value and the measured one of the reflection loss. For the metallic powders, copper powder showed good agreement between the calculated and the measured of reflection loss. For the magnetic material, it was concluded that the theoretical formula under consideration of complex permeability μr* should be derivated.