1. A personal service support method for assisting an inquiry about a user operation in a virtual world, the method comprising the steps of: storing a dialog between a user and an agent, wherein said agent answers said inquiry about the user operation to produce a stored dialog; connecting said dialog in said list structure with another dialog in said list structure to produce a created dialog in a branch tree structure based on the stored dialog having a list structure in which dialog units of said user and said agent are set as nodes and based on information on said nodes; and recording said created dialog in said branch tree structure thereby assisting an inquiry about user operation in said virtual world.