A droplet jet head includes a nozzle substrate having a plurality of nozzle holes; a cavity substrate having recesses whose bottoms serve as diaphragms, and the recesses serving as ejection chambers; an electrode substrate having separate electrodes opposed to the diaphragms; a reservoir substrate having a recess serving as a common droplet chamber for supplying droplets to the ejection chambers, through holes for transferring the droplets from the common droplet chamber to the ejection chambers, and nozzle communicating holes for transferring the droplets from the ejection chambers to the nozzle holes; and a driver IC that supplies a driving signal to the separate electrodes. The cavity substrate has a first hole, and the reservoir substrate has a second hole. The first hole and the second hole communicate with each other to form a housing. The driver IC is housed in the housing.