This study intended to clarify the current status of ethical consumption behavior and relating factors. The authors conducted a web-based survey for the members of “Pal System Consumers’ Cooperative Union,” which provided a wide variety of commodities and services designed to promote ethical consumption including environmentally friendly items, organic foods, and electricity from renewable sources. To identify the total image of ethical consumption behavior and priority issues for its promotion, Bayesian Network modeling, which proves effective in prediction and classification on various fields, was applied to develop the determinant models of ethical consumption behavior. The authors also quantified the expected effects of predictors based on the sensitivity analyses of the structure models. Regarding “Purchase behavior of organic products,” it was suggested that “consciousness of label for Organic foods/GMO at point of purchase” would have the largest impact and improve the involvement level by 20%.