PROBLEM TO BE SOLVED: To provide a liquid administration device which makes it possible for even a user having difficulty in pressing and operating of an operating member to administer liquid easily and reliably, and can prevent discharging of the liquid from a tip of a needle pipe when the administration of the liquid is suspended.SOLUTION: A liquid administration device 10 comprises: an inside structure comprising a tube body having a bottom at a tip and an opening at a proximate end and inside of which can be filled with liquid, a needle pipe mounted on the tip of the tube body, having a sharp needle tip at the tip, and whose proximate end can communicate with the inside of the tube body, and a gasket which is provided in the tube body and can slide along an axial direction of the tube body an operating member having a plunger pressing the gasket and performing pressing force operation to discharge the liquid from the needle pipe by shifting the plunger in a tip direction a supporting system generating supporting force to press the gasket through the plunger and a supporting force transmission inhibition system preventing transmission of the supporting force to the gasket in the course of the pressing force operation.
