A liquid jet head chip comprising: an actuator plate having an obverse surface (51f1), a reverse surface (51f2), and two or more ejection channels which penetrate the actuator plate in a thickness direction (Y) from the obverse surface toward the reverse surface, which are disposed so as to be adjacent to each other at intervals in a first direction (X) perpendicular to the thickness direction and which are disposed so as to extend in a second direction (Z) perpendicular to both of the thickness direction and the first direction; and an electrode disposed on an inner surface of each ejection channel, wherein each electrode includes: a first electrode part covering the inner surface of the ejection channel continuously from the obverse surface toward the reverse surface; and a second electrode part covering the inner surface of the ejection channel continuously from the reverse surface toward the obverse surface, and overlapping at least a part of the first electrode part, wherein each ejection channel has a closed end at one end of the ejection channel in the second direction (Z), characterized in that the closed end is including an exposed part in which the second electrode part is not formed and the inner surface of the ejection channel or the first electrode part is exposed, and wherein the first and second electrode parts overlap along the length of each ejection channel , except at the exposed part of the closed end, to form a common electrode . an actuator plate having an obverse surface (51f1), a reverse surface (51f2), and two or more ejection channels which penetrate the actuator plate in a thickness direction (Y) from the obverse surface toward the reverse surface, which are disposed so as to be adjacent to each other at intervals in a first direction (X) perpendicular to the thickness direction and which are disposed so as to extend in a second direction (Z) perpendicular to both of the thickness direction and the first direction; and an electrode disposed on an inner surface of each ejection channel, wherein each electrode includes: a first electrode part covering the inner surface of the ejection channel continuously from the obverse surface toward the reverse surface; and a second electrode part covering the inner surface of the ejection channel continuously from the reverse surface toward the obverse surface, and overlapping at least a part of the first electrode part, a first electrode part covering the inner surface of the ejection channel continuously from the obverse surface toward the reverse surface; and a second electrode part covering the inner surface of the ejection channel continuously from the reverse surface toward the obverse surface, and overlapping at least a part of the first electrode part, wherein each ejection channel has a closed end at one end of the ejection channel in the second direction (Z), characterized in that the closed end is including an exposed part in which the second electrode part is not formed and the inner surface of the ejection channel or the first electrode part is exposed, and wherein the first and second electrode parts overlap along the length of each ejection channel , except at the exposed part of the closed end, to form a common electrode . <EOS>