This study aimed at exploring the effects of two great accidents (the explosion of the space shuttle “Challenger” and the disaster of Chernobyl nuclear power plant) on the evaluation and the image of each technology. Before and after each accident, questionaires were administered to university students. In this article, we reported only about the evaluation and the image of three technologies: space development, nuclear power generation, and artificial intelligence. Though the comparison should be carefully interpreted because the sampling was not systematic, some points were suggested. First, the accident of Challenger affected the evaluation and the image of space development very strongly, and also artificial intelligence a little. However, the accident of Chernobyl had an effect only on nuclear power generation. Second, after the accident of Challenger, safety evaluation of space develpment shifted negatively, though general and social evaluation changed positively. On the other hand, after the accident of Chernobyl nuclear power plant, all evaluation of nuclear power generration changed negatively.