In this paper we propose a theoretical study on the design of a THz filter using FSSs based on metamaterial wire resonators. The present approach is a simpler design which makes use of only two FSSs but provides enhanced frequency selectivity. The proposed filter consists of a resonant double wire metamaterial array whose equivalent circuit is shown in Fig.1a). The wires can be tuned so that only evanescent modes exist in the vicinity of the structure, allowing us to control the energy transmission and reflection. A diagram illustrating the allowed modes of the structure is shown in Fig. 1b). By appropriate choice of the wire radius a and distance between wires d we can control the position of the modes in the diagram allowing us to design highly selective filters with very high Q factor.