A fast simulation tool of Eddy Current Testing (ECT) inspections, based on a Boundary Element Method (BEM), is proposed in this paper. Simulated signals consist of impedance variation of a coil due to multiple narrow cracks located in conductive planar multilayered structures (MLS). The cracks can have various shapes or orientations and can lie in any layer of the structure inspected. After a presentation of the method, validations results, consisting of comparison of simulated signals with experimental data and results obtained with finite element calculations, are presented. In all the problems tested, a very good accuracy and a very low computation time have been observed. Further perspective and conclusions of this work are detailed at the end of the paper.