In Japan consumers' fears about food safety have been heightened concerning imported food after the Chernobyl nuclear reactor accident in 1986. The purpose of this study is to clarify consumers' fears about food safety and risk perception. The survey was carried out to have consumers and experts estimate the ranking of the risk of 10 potentially toxic substances. The major results are as follows. 1) The consumer evaluates radioactive substances and environmental contaminants to be the most risky. On the other hand，the expert evaluates agricultural chemicals，mycotoxins and microbes，which cause frequent daily accidents，to be equally as risky as the previous two substances. The evaluation of microbes and mycotoxins is greatly different between the consumer and the expert. 2) The consumer's risk rating is strongly influenced by serious accidents which have caused social problems in the past，whereas the expert's rating is mostly based on actual accident frequency and fatalities. 3) The result of the cluster analysis shows the tendency of irradiated food to be confused with radioactive substances，or to be regarded as the same thing.