A piezoelectric member includes a flat part and a plurality of convex parts on the flat part, and at least a part of each convex part is a piezoelectric element. A non-piezoelectric member is made of non-piezoelectric materials, and includes a plurality of concave parts corresponding to the piezoelectric elements and a convex part formed between adjacent concave parts. The piezoelectric member and the non-piezoelectric member are engaged with each other by inserting each non-piezoelectric convex part between adjacent piezoelectric elements and an ink cavity is formed between a bottom surface of each concave part and a top surface of each piezoelectric element. Also between a side of the piezoelectric convex part and a side of the non-piezoelectric concave part is provided a space, and the space is filled with a filler.