PURPOSE: To prevent the pressure in an inner container from falling into a dangerous condition even though a steam discharge passage is blocked or an electrical heater falls in an abnormally heating condition.

CONSTITUTION: In an electric water heater in which a lid 2 is attached to the top end part of a body casing 1 incorporating an inner container 6 for reserving therein hot water boiled by an electric heater 9, and a pressurizing type bellows pump 10 for introducing hot water from the inner container 6 is provided in the lid 2, a steam discharge passage 22 for discharging steam produced in the inner container 6 to the outside while bypassing the inside of the bellows pump 10 is provided. Further, a temperature sensor 20 for detecting a boiling temperature so as to control the current to the electric heater 9.