The present invention relates to a liquid jetting head, a liquid jetting
apparatus, and a method of manufacturing the liquid jetting head. The
invention can be particularly adopted to an ink jet printer of a thermal
system. A treatment for building up a coating type insulating material
film and a treatment for substantially removing the insulating material
film in the forming regions of heating elements by etching are repeated
at least a plurality of times, whereby deterioration of the heating
elements can be prevented even in the case where generation of steps is
prevented by an SOG film.