In this paper a formulation for the solution of the electromagnetic field in stratified structures with an istropic chiral grounded slab under planar electric excitation conditions is presented. The development of the solution is obtained by using the two-dimensional (Fourier) transform applied to the partial differential equations describing the electromagnetic field, expressed in terms of dyadic electric Green's function. Moreover, a spectral equivalent circuit representation of the solution, separated into its spectral transverse electric (TE) and transverse magnetic (TM) components (with respect to the vertical direction), is given. Noteworthy reciprocity properties among the elements of the spectral dyadic Green's function are presented together with the determination of the degrees of freedom of the structure. Finally, an example of this theory applied to an electric vertical point source disposed at the interface plane between the chiral slab and the homogeneous istropic upper half-space is given with the evalution of the radiated pattern.