Liquid discharging head and ink-jet apparatus

A method for producing a liquid discharging head, wherein

• the liquid discharging head includes:
• a nozzle configured to discharge liquid;
• a pressure chamber communicated with the nozzle;
• an individual channel communicated with the pressure chamber through a narrow part;
• a common channel communicated with the individual channel;
• an energy generation element configured to generate energy;
• and
• a diaphragm configured to convey the energy to the pressure chamber, the method comprising:
• forming a metal oxide film at each of an inner wall of the nozzle, an inner wall of the pressure chamber, an inner wall of the narrow part, an inner wall of the diaphragm, and an inner wall of the individual channel,
• wherein a hydroxyl group has come out from the metal oxide film.