Though the computer science industry has become more and more important in recent years in Germany and elsewhere, the number of students in IT-related study programs is increasing only slowly. This results in a shortage of skilled IT workforce. Additionally, women are strongly under-represented. A possible cause of these phenomena are stereotypes towards people in computer science. But what image of computer scientists do students at German secondary schools really have? In order to get an overview, 52 upper-secondary school students were surveyed by using an online questionnaire, which included both open-ended and closed questions. The results show that the conceptions are very diverse and individual. However, some characteristics are considered more appropriate than others. For example, many students indicated that people in computer science are intelligent and good at maths and science. Fewer stated that they are team players and have good communication skills. The analysis of subgroups show tendencies that aspects such as gender, previous school experience and interest in computer science, and the personal environment of the students can influence these conceptions.