The present invention offers a means for sustained release of liquid making it possible to continue to stably and efficiently administer liquid like medical solution also to a diseased region which exists on a luminal wall surface against gravity, making it possible to easily move the means after administration of liquid, making it possible to optionally adjust an amount of administration of the liquid and administration rate of the liquid, and making it possible to administer plural kinds of liquid in turn an endoscope having the same and an instrument for endoscopic surgery having the same.An means for sustained release of liquid according to the present invention includes: an outer pouch-shaped elastic member 2 an inner pouch-shaped elastic member placed inside the outer pouch-shaped elastic member and capable of being inflated a liquid-holding section 3 holding liquid between the inner pouch-shaped elastic member and the outer pouch-shaped elastic member and minute holes provided for the outer pouch-shaped elastic member, the diameter of the minute holes being changed by inflation and deflation.
