We investigate how an increase in the robot intensity (the ratio of industrial robots over employment) affects the self-reported mental health of workers in Germany. To do so, we combine individual mental health data from the German Socioeconomic Panel with the deliveries of robots to 21 German manufacturing sectors provided by the International Federation of Robotics for the period 2002-2014 (every two years). Controlling for a range of individual and sectoral characteristics, and employing individual-, time-and sectoral fixed effects, we find that an increase in robot intensity of 10% is associated with an average decrease of 0.59% of the average mental health standard deviation. This suggests that in a fast automating sector (i.e. rubber and plastics), where the robot intensity increased by approximately 2000%, mental health would have decreased by 118% of one standard deviation. This effect seems to be driven by job security fears of individuals working in noninteractive jobs and the fear of a decline in an individual's economic situation. Moreover, further sample divisions into low, middle and high occupational groups shows that the negative effects are affecting mostly the middle-level occupational group. Splitting the sample according to different age groups shows that the mental health of younger workers is the most vulnerable to an increase in automation. Results are also robust to instrumenting the stock of robots, and to different changes in the sample.