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 for 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 for determining the reply sentence based on the conversation scenario when requested to send the determined reply sentence to the conversation device for an output of the reply sentence to the user, the conversation scenario editing device comprising: an editor configured to check whether or not an appropriate state transition relation is maintained in the conversation scenario edited thereby for editing the conversation scenario; a language model generator for calculating occurrence possibility of a word string of the input sentence within the conversation scenario edited by the editor and generating, based on a calculating results thereof, a language model to be used when the conversation device executes the speech recognition; and a timer to check a state where a predefined time period has elapsed without an utterance by the user, wherein the editor edits the conversation scenario to include a reply sentence corresponding to the state where a predefined time period has elapsed without an utterance by the user, wherein the reply sentence corresponding to the state where a predefined time period has elapsed without an utterance by the user is a suggestion for leading the user to select a route in the conversation scenario and wherein, in a case where a violation of the appropriate state transition relation occurs in the conversation scenario, the editor generates a message for notifying present of the violation and the input sentence or the reply sentence causing the violation to an operator and then displays the message on an output unit.