This work focuses on Green Functions (GFs) of planar multilayered structures that may include arbitrary number of conductive sheets. The spectral domain GFs are derived through an automatized strategy based on the propagator matrix technique, while the spatial domain counterparts are evaluated numerically using a novel, efficient and error controlled numerical method. All the procedures remain general to accommodate for the tensorial nature of the conductivity of the sheets. Numerical examples of GFs for the Mixed Potential Integral Equation method are provided validating the proposed algorithms. © 2014 IEEE.