Abstract-In this paper a new technique for the evaluation of the Green's functions of filament sources in layered media, is presented. The technique is based on the annihilation of the asymptotic and singular behaviors of a spectral Green's function. The remaining function, after annihilation, is treated using a two levels discrete complex image method (DCIM). The application of the proposed technique, provides a complete analytical expression for the spatial Green's function, in terms of the iterative value of the propagation constant. This expression consists of the annihilating functions and a number of complex images. In order to validate the proposed technique, microstrip lines and slotlines are analyzed and the obtained results are found to agree very well with those obtained using a commercial software.