1. A conversation scenario editing device for an automatic conversation system using a conversation scenario, the automatic conversation system including a conversation device and a conversation server, the conversation device generating an input sentence through speech recognition of an utterance by a user and requesting the conversation server to send a reply sentence to the input sentence, and the conversation server determining the reply sentence based on the conversation scenario when being requested to send the determined reply sentence to the conversation device for an output of the reply sentence to the user, the editing device comprising: a language model generator for generating, based on the conversation scenario, a language model to be used when the conversation device executes the speech recognition.