The authors of this paper analysed Acoustic Emission (AE) signal generated in different stages of punch process, emitted from crank PMSC - 12 punch press. The details of the instrumentation used are described. The experimental part describes the influence of feedstock thickness and hardness to the intensity of the emitted signal. The final part of the investigation presents the changes of AE signal caused by simulated tool abrasive wear. The possibilities of AE monitoring of punching of thin plates are also discussed.