An ink jet head having a head chip with drive walls made of piezoelectric elements and channel portions alternately arranged in parallel; a top-side and a bottom-side base plates each formed to be longer than the channel portions and fixed on an upper and lower surfaces of the head chip; an ink supply room forming member for forming an ink supply room to supply ink to each of the channel portions; first lead wires to be connected to their respective drive electrodes formed on the drive walls, said first lead wires being formed on a fixed surface of the head chip to be fixed to the base plate; and second lead wires to be connected to the first lead wires, said second lead wires being formed on the surface of the top-side and/or the bottom-side base plate at the side of the fixed surface of the head chip.