This liquid-heating heater includes: a main body made of metal and having a liquid flow passage through which a liquid flows, and a tubular section that is integrally provided on the outside of the liquid flow passage and that houses a heat generating unit; and a sealing body that closes an end of the tubular section. The heat generating unit includes: a PTC element having an electrode surface; an electrode plate attached to the electrode surface; and an insulating body provided between the electrode plate and an inner wall of the tubular section and overlaid on the electrode plate. The heat generating unit is tightly held between the inner walls of the tubular section. There is no clearance between the liquid flow passage and the heat generating unit, and a portion of the main body exists integrally therebetween.
