pressure to the ink stored in the pressure chambers 220 the ink discharging unit 100 may further include an oxide layer more specifically the oxide layer may be formed on a surface of the ink discharging unit 100 the oxide layer formed as described above may block an electric connection between the ink discharging unit 100 and another member the ink discharging unit 100 may include a plurality of substrates for example the ink discharging unit 100 may include a first substrate 110 a second substrate 120 and a third substrate 130 here the first substrate 110 the second substrate 120 and the third substrate 130 may be sequentially stacked and be formed of single crystalline silicon the first substrate 110 may form a lower layer of the ink discharging unit 100 the first substrate 110 may be formed of a single crystalline silicon substrate or a silicon on insulator soi substrate as needed alternatively the first substrate 110 may be a laminated substrate in which a silicon substrate and a plurality of insulating members are laminated the first substrate 110 may include a plurality of the nozzles 210 each of the nozzles 210 may be formed to extend in a thickness direction a z axis direction based on fig1 of the first substrate 110 the nozzles 210 may be formed at predetermined intervals in a length direction a y.