An ink jet head has a plurality of individual head chips integrated to form a head chip block. Each head chip has a plurality of grooves, and the grooves of all the head chips open at one end to respective nozzle holes formed in a nozzle plate. Each head chip has an actuator substrate in which is formed an ink chamber that supplies ink to the grooves in that head chip. An ink flow path connects an ink supply to one of the ink chambers in one of the head chips, and the ink chambers of all the head chips communicate with one another through ink holes. Since ink is supplied to the grooves of all the head chips from a single ink flow path connected to the ink supply, the size of the ink jet head, particularly in the thickness direction, the weight, the number of parts and the manufacturing cost can all be reduced.