Member having ultrafine groove, member for passage, method of manufacturing the same, ink jet printer head using the same, and ink jet printer head

A member 10 having ultrafine groove of high density and high precision is obtained in a simple process. On one side of a flat plate 11 made of ceramics, glass, silicone or the like, a partition wall 12 obtained by forming powder of ceramics, glass, silicone or the like by a molding die having a recess is bonded and integrated, and a member 10 having ultrafine groove is composed. A member for passage 110 of high density and high precision is obtained in a simple process. On one side of a flat plate 111 made of ceramics, glass, silicone or the like, a partition wall 112 obtained by forming powder of ceramics, glass, silicone or the like by a molding die having a recess is bonded and integrated, and a member for passage 110 is composed by forming a passage 113 between partition walls 112. In an ink jet printer head comprising plural ink chambers 201, an ejection port 206 communicating with the ink chambers 201, and a diaphragm 221 for applying a pressure to the ink chambers 201, the displacement of a piezoelectric element 201 is favorably transmitted to the diaphragm 221, and the manufacturing process is simplified. The diaphragm 221 is formed of conductive inorganic material, and a piezoelectric element 203 is bonded to the diaphragm 201, and a driving electrode 204 is formed on this piezoelectric element 203.