The article presents the comparison of two methods of microwave data analysis for evaluation of moisture content in porous materials. The content of the paper covers the short description of microwave technique for moisture evaluation and the description of the two methods of microwave data analysis – the time domain and frequency domain. In the second part, the dependences between red brick moisture and apparent permittivity are presented. Apparent permittivity values are determined by microwave antenna and calculated in time and frequency domain. With the calculated values, regression models were estimated and quality of both evaluated. Using the analyzed data, the advantages and disadvantages of both techniques were defined and the measuring potential evaluated.