This paper proposes a method for automatically generating postcards that reflect each visitor’s museum experience by analyzing the log of our original iPad app that supports and guides personalized navigation in the National Museum of Ethnology. Museum experiences have become more personalized with the evolution of guiding devices. Each visitor views the different exhibits in a different order. Souvenirs serve to remind visitors of their museum experience and cement it in their memories; thus, souvenir postcards should be tailored to each visitor’s museum experience. Such tailored postcards can effectively remind visitors of their experiences, deepen their impressions when they look back at them, and promote post-learning. In this paper, we proposed a system that automatically generates a postcard for each visitor for each visit by selecting the five most relevant and impressive exhibits based on the search and navigation logs on our museum guide app. We analyzed the search logs of the guide devices based on the psychological effects on impressions and memory to estimate which exhibits had the strongest impact on the visitors. We then conducted an in laboratory controlled user experiment with 16 participants to check what exhibits had made an impression on visitors by using the implemented system. The results showed that the exhibits that were seen frequently and the exhibits that participants added to their favorites were the most memorable.