This paper presents the initial study of microwave tomography in agriculture to investigate the effect of microwave signal on the thickness of a medium. In this project, a pair of antennas is used non-invasively where one of it acts as a transmitter and the other one as a receiver. The investigation was based on the transmission and reception of antennas in a transversal direction while several samples of mediums with different thickness are put between those antennas. The result obtained throughout this initial study had shown that the attenuation of microwave will vary with the diameter of the medium. The information and analysis of the preliminary results can be used as a reference for further investigation on the selected medium.