103 is liable to be retained at a portion higher in capillary force of the ink absorbing materials 102 a and 102 b for this reason as shown in fig5 and 6 the ink 103 is gradually consumed while being attracted to the neighborhood of the interface 104 this is because as described above in the neighborhood of the interface 104 the compression ratio is higher than those of other portions of the ink absorbing materials 102 a and 102 b thus resulting in a higher capillary force as a result the ink 103 is collected in the neighborhood of the interface 104 so that the ink 103 remaining at other portions of the ink absorbing materials 102 a and 102 b can be reduced further the ink absorbing materials 102 a and 102 b press contact the filter 106 as described above so that the ink 103 retained in the neighborhood of the interface 104 is attracted to the neighborhood of the press contact portion between the ink absorbing materials 102 a and 102 b thus being supplied to the ink introducing passage 111 formed by the ink introducing portion 105 in this embodiment the filter 106 is provided to the end of the.