<p>A syringe adapter (300) is provided with a base member (310) and a flange lock member (320). The flange lock member (320) as a whole is formed in a substantially circular arc shape so as to receive a cylinder flange to the inner side of the flange lock member. The flange lock member (320) has formed thereon lock claws (323) which, when a syringe received by the flange lock member (320) is rotated about the axis thereof, lock the cylinder flange, and engaging claws (324) which lock the syringe adapter (300) to a device in such a manner that the lock to the device is not released when the cylinder flange of the syringe is being received by the flange lock member (320).</p>
