This paper will introduce the new technique to design new type of microwave absorber. Microwave absorbers are used in anechoic chamber to diminish the unwanted RF signal, so that the measurement obtain have perfect and good results. The basic theories of slot antenna combining with the theory of microwave absorber are used in this paper. As a result of studies, the new design called as the slot radial array design on hollow pyramidal microwave absorber. The design of pyramidal microwave absorber and the slot was introducing in this paper. The simulation process was done by using CST software. The new design of the absorber was measured to make sure it can be compared in terms of the performance. Lastly, the performance of new slot radial array design pyramidal microwave absorber will be analysed by identifying the characteristics performance. The Slot Radial Array proved to be as one of the way to improve the performance.