It is difficult to accurately express discomfort with words. These days, a method of evaluating feeling with biological information such as heartbeat has been proposed. We will apply this method to evaluate for the hospitability service behavior robot that would be difficult to express the feeling with words, and its effectiveness is not clear. Therefore, in this research, we assumed the service of robots as hospitality behavior and aimed to verify the effectiveness of hospitality behaviors by making impression evaluation based on heartbeat information at that time of service. In realizing the objective, we analyzed the change of the heartbeat when judging comfort/discomfort at the time of hospitality behavior using the evaluation index pNN50 that is used for comfort/discomfort judgment. As a result, we obtained the first step result that shows the biological information to evaluate the feeling of discomfort and comfort state of the people for hospitable robot.