Abstract: There is provided an insert method of a negative-pressure generating member where, upon inserting a negative-pressure generating member 130 into a negative-pressure generating member accommodating chamber, the negative-pressure generating member 130 is inserted while being rotated to a predetermined rotation angle, is inserted to the bottom portion in the negative-pressure generating member accommodating chamber while retaining the rotated angle, and further, is inserted by rotating the negative-pressure member 130 in a reverse direction to the previous rotation direction, thereby increasing a density of the negative-pressure generating member in the partition wall adjacent section.