People regard robots as social entities and apply social rules to the relations between people and robots. Robots, however, project an amount of product-ness and robot-ness as well as humanness. The objective of this study is to examine how people perceive robots as social objects by comparing with other objects. In order to investigate the effect of intergroup relations on peoples acceptance of robots by types of objects, social distance, especially intergroup relations, was applied to this study. In an experiment, participants watched pictures of in-group and out-group stimulus drawn from four types of objects (robots vs. humans vs. animals vs. products) and rated it in terms of preference and reliability. The results from the experiment showed that the difference of preference score between in-group and out-group in the case of robots was significantly greater than in the case of animals and products which are owned by people. In the case of reliability, intergroup relations had more of an influence on robots than humans. Based on the experiment results, we discussed the use of intergroup relations for designing robots.