PURPOSE: To provide an enameled vessel body having superior hot water resistance by forming the 1st enamel layer contg. SiO2, B2O3 and other contg. compds. on the inside surface of a steel plate constituting the vessel body and further forming the 2nd enamel layer contg. SiO2 and other inorg. compds. thereon.

CONSTITUTION: The 1st enamel layer 7 constituted of the glaze contg. 30W40% SiO2, 10W20% B2O3 and other inorg. compds. is formed on the inside surface of a steel plate 6 constituting a vessel body 1 for electric water heater. The 2nd enamel layer 8 constituted of the glaze contg. no B2O3 at all and contg. 60W 70% SiO2 and other inorg. compds. is further formed on said layer 7 on the inside surface of the steel plate 6 in the part upper than the heater 2 of the body 1. As a result, the layer 8 develops higher resistance force to hot water than the layer 7 and contributes to the marked prolongation of the life of the body 1 itself. Here, 3 in the figure denotes a hot water feed port, 4 a water feed port, and 5 an electrode bar for electrolytic protection.