A stent inserting device is used in inserting a self-expandable stent with leading and trailing ends into a tubular organ of a living body. The stent inserting device includes a grip body, an external tube attached to a front end of the grip body, a push member movably inserted into the external tube from a rear end of the grip body, and a tubular cap for removably receiving the stent in a compressed state. The tubular cap has a front end operatively connected to the push member and a rear end slidably fitted to a front end of the external tube. The stent inserting device is designed to hold the stent within the tubular cap in such a manner that the stent is first expanded at the trailing end and then gradually expanded toward the leading end when the tubular cap is pushed away from the external tube.