Nonlinear surface wave propagation properties for a symmetric planar antiferro-magnet/superconductor/antiferromagnet waveguide are theoretically investigated. The attenuation constant and the phase constant, in the infrared frequency region, are numerically analyzed as a function of the thickness of superconductor. It is seen that both the attenuation constant and the phase constant decrease with increasing the thickness of superconducting film. In addition, numerical result in the total power flow reveals the existence of a threshold value in the propagation constant. Electromagnetic wave can propagate in the waveguide when propagation constant is greater than this threshold value.