The ever-increasing complexity of robot applications induces the need for methods to approach problems with no (viable) analytical solution. Deep learning (DL) provides a set of tools to address this kind of problems. This survey presents a categorization of the major challenges in robotics that leverage DL technologies and introduces representative examples of successful solutions for the described problems. We also consider the question when and whether to use modular, monolithic models or end-to-end DL, in order to provide a guideline for the selection of the correct model structure and training strategy. By doing so, the current role and adaptability of different techniques at different hierarchical levels of a robot-application can be highlighted, thus providing a well-structured basis to assist future approaches. Index Terms-Deep learning (DL), machine learning (ML), manipulators, mobile robots, neural networks, robot control, robot learning. I. INTRODUCTION C OMPUTERS can easily solve formal problems that are demanding for humans. However, the increasing need for adaptive systems requires the solution of tasks that are hard to formulate, but can be easily solved by humans, such as the recognition and manipulation of objects. In order to perform such tasks, a certain complex knowledge of the environment is inevitable. The automatic extraction of the required knowledge is called machine learning (ML). The way the data is presented to the ML system, heavily influences how well the extracted knowledge represents the given problem. The ML approaches that also perform feature extraction, using multiple hierarchical artificial neural network layers, are referred to as deep learning (DL) [1], [2]. The theoretical background of DL had been introduced for a long time, when it finally gained widespread popularity, i.a., thanks to the winner entry of the ImageNet Challenge Manuscript