PURPOSE: To secure a discharge recovering operation by performing an idle suction through an absorbant with a cap released from the surface of an orifice in addition to absorbing a liquid by the liquid absorbant therein.

CONSTITUTION: When an orifice 2 is positioned to face a cap 3, first, the cap 3 advances and an absorbant 10 begins to contact the orifice 2. With the compression of the absorbant 10, an elastic member 4 gets tight on the orifice 2 completely and a suction operation is performed with a pump or the like. After a negative pressure suction operation is done, the cap 3 separates from the orifice 2 in time while an idle suction is done. With the idle suction, the liquid contained in the absorbant 10 is also sucked thereby eliminating excess liquid in the absorbant 10. Thus, there is not trouble such as drying of liquid in the absorbant 10.