<p>A needle-stent device comprising: an inner needle having a sharp needlepoint at the tip thereof; an inner needle hub fixed to the basal part of the inner needle; a hollow outer needle into which the inner needle is to be inserted; an outer needle hub fixed to the basal part of the outer needle; a tube connected to the basal part of the outer needle so that the inner cavity thereof is communicated with the inner cavity of the outer needle; an opening formed at the basal part or the side part of the outer needle so as to communicate with the inner cavity of the outer needle; a handling part which is formed in the outer needle and by which the inner needle and the outer needle are moved in the longitudinal direction thereof when the inner needle is inserted into the outer needle; and a locking means which is switchable, when the inner needle is inserted into the outer needle, between a locked state (i.e., the inner needle hub being locked to the outer needle hub) and an unlocked state (i.e., the locking being released).</p>
