The objective of this study was to investigate the perceptions and purchase behaviors on foreign matters in food. For that, we conducted a survey of 348 adults living in a metropolitan area. Concern over the presence of foreign matters in food was a lower than that for other harmful factors such as heavy metals, BSE, harmful microbes and so on. 70% of respondents would not take the snack which was detected a rat’s head, including the manufacturer’s product and similar products with it after the foreign matter incident. In contrast, about of 54% respondents were willing to buy canned tuna after the incident. It is necessary to prepare more detail management and policy on foreign matters in food.