Liquid jet head, liquid jet apparatus and method of manufacturing liquid jet head

A method of manufacturing a liquid jet head comprising:

• an ejection groove forming step for cutting a piezoelectric substrate from an upper surface of the piezoelectric substrate using a dicing blade to form a plurality of elongated ejection grooves;
• and
• a non-ejection groove forming step for cutting the piezoelectric substrate from a lower surface opposite to the upper surface of the piezoelectric substrate using a dicing blade to form a plurality of elongated non-ejection grooves in parallel to a groove direction of the ejection grooves,
• wherein a plurality of groove rows in each of which ejection grooves and non-ejection grooves are alternately arranged in a reference direction are formed, and, in adjacent ones of the groove rows, ends on a second side of ejection grooves included in a groove row located on a first side and ends on the first side of non-ejection grooves included in a groove row located on the second side are separated from each other, and overlap each other in a thickness direction of the piezoelectric substrate.