In order to explore the applications of single negative meta-materials (SNM) in wireless system, the electromagnetic properties of composite structure constructed by the SNM and air are investigated by means of transfer-matrix method. The results show that the tunneling phenomenon will happen in the sandwich structure composed of epsilon-negative meta-materials (ENM), mu-negative meta-materials (MNM) and air under proper parameters. In addition, the electric and magnetic fields are localized at different interface respectively and the electric field is localized at the interface of MNM and air but the magnetic field is at the interface of ENM and air. With these features, the present structure may have important potential applications in wireless transmission.