The present invention relates to an apparatus comprising a reactor body to which gas and water are supplied to create a gas hydrate; an upper cover which is engaged to an upper portion of the reactor body, a scraper mounted rotationally within the reactor body, and a motor for providing a driving force to the scraper. It is possible to remove gas hydrate particles attached to at least one of an inner surface of the reactor body and an inner surface of the upper cover, by a rotary driving of the scraper. According to the invention, it is possible to prevent a material hindering a heat transfer by attaching on a wall surface of the reactor, through a process of scraping out gas hydrate particles, when the scraper which is rotationally driven about a center axis of the reactor is close to the inner surface of the reactor.