The AES is a standard encryption algorithm used in numerous cryptographic systems like smart cards, TPMs as well as in protocols like WPA2 or OpenSSL. Measuring the robustness of AES implementations against physical attacks is of utmost import-ance in order to guarantee the security of the system into which the AES is used. In this article, we describe how a hardware AES, embedding countermeasures against physical attacks, has been characterized using a laser. With the latter, we tried to implement a class of physical attacks called fault attacks which, when successful, allows an attacker to retrieve the secret key used by the AES module. Our experiments have allowed us to validate the efficiency of some of the countermeasures implemented in this AES implementation and have given us hints on how to further improve them.