With an operation information supplement instructing unit (16), a service progress dependent information storage unit (11), a service progress dependent information search unit (12) and a service progress dependent information answering unit (13) provided, when the operation information supplement instructing unit (16) is pressed, the service progress dependent information search unit (12) searches the service progress dependent information storage unit (11) for supplemental contents recorded in pair with the same service progress as a current service progress (information indicating how far service progresses) and presents the searched supplemental contents to a user through the service progress dependent information answering unit (13).