In a method of manufacturing a multi-nozzle ink jet head having a plurality of nozzles, cross talk between adjacent elements is suppressed. The head has the nozzles (12), pressure chambers (15), and bimorph drivers. The bimorph drivers have piezos (19) formed on a diaphragm (18). The diaphragm (18) has linear parts (18-1) that convert the generated force from the piezos (19) into displacement, and non-linear parts (18-2) that are provided between the linear parts (18-1) and diaphragm fixing parts. Due to the non-linear parts (18-2), transmission of strain energy to the fixing parts is suppressed, and hence cross talk is suppressed.