This paper focuses on how peace education at a peace museum is promoted by a volunteer guide service for visitors. Peace museums are places where many materials related to war and peace history are on display. To support the learning experience of museum visitors, many peace museums in Japan provide a volunteer guide service. The Kyoto Museum for World Peace, Ritsumeikan University, started such a service more than 20 years ago. A citizens' group, called Friends for Peace, is in charge of the museum guide activities in cooperation with the museum. This article explains the purposes and nature of the service, and also reports on a survey of similar services offered by other peace museums in Japan.