This paper reports an ethnographic study on the use of a conversational robot. We placed a robot for 3.5 months in an elderly care center. Assuming a real deployment scenario, the robot was managed by a single non-programmer person during the field trial, who teleoperated the robot and updated the contents. The robot was designed to engage in daily greetings and chatting with elderly people. Through the ethnographic approach, we clarified how the elderly people interacted with this conversational robot, how the deployment process adopted to introduce the robot was designed, and how the organization's personnel involved themselves in this deployment.