Thermographic inspection is a popular nondestructive testing (NDT) technique that provides direct images of temperature distribution over large areas at the surfaces of inspected objects. A major application of this method is the inspection of composite materials during manufacturing or in service, in view of detecting delaminations possibly appearing between the layers of the structure [1]. Simulation of these inspections proves useful to complement experimental studies, evaluate the performance of a given setup in terms of detection and support model based algorithms aiming at characterizing flaws. This communication presents a 3D semi-analytical model to address the special case of planar stratified media.