Title: Adversarial Feature Desensitization. Abstract: Deep neural networks can now perform many tasks that were once thought to be only feasible for humans. While reaching impressive performance under standard settings, such networks are known to be  susceptible to  adversarial attacks -- slight but carefully constructed perturbations of the inputs which drastically decrease the network performance. Here we propose a new way to improve the network robustness against adversarial attacks by   focusing on robust representation learning based on  adversarial training procedure, called here Adversarial Feature Desensitization (AFD). AFD desensitizes the representation via an adversarial game between the embedding network and an adversarial discriminator introduced on top of  the standard predictive model, which is trained to distinguish between the clean and perturbed inputs from their high-level representations. Our method substantially improves the state-of-the-art in robust classification on MNIST, CIFAR10, and CIFAR100 datasets. More importantly, we demonstrate that AFD has better generalization ability than previous methods, as the learned features maintain their robustness across a wide range of perturbations, including perturbations not seen during training. These results indicate that reducing feature sensitivity is a promising approach for ameliorating the problem of adversarial attacks in deep neural networks. 