A method of manufacturing an ink-jet printhead, including forming an insulation film on a substrate, depositing a metal layer onto said insulation film and patterning said metal layer to form a heater, forming an electrical wire on said substrate, etching said substrate at a predetermined depth from a top surface of said substrate in a direction perpendicular to a major surface of said heater to form a narrow passage, depositing an ink chamber barrier layer on said top surface of said substrate and patterning said ink chamber barrier layer to form an ink chamber, stacking a nozzle plate having a nozzle on said ink chamber barrier layer and disposed on an upper portion of said ink chamber barrier layer, and applying predetermined pressure and temperature onto said nozzle plate to bond said nozzle plate and said substrate, and etching said substrate from a bottom surface thereof to form a wide passage communicating with said narrow passage.