A steam cooker includes a steam generator for generating steam, a steam temperature-raising device for raising a temperature of steam coming from the steam generator, and a heating chamber in which an object to be cooked is heated by steam supplied from the steam temperature-raising device. The steam generator has a pot (41) to which water is supplied, a heater (42) placed in the pot (41), a water level sensor (43) and a temperature sensor (48) placed in the pot (41). The water level sensor (43) and the temperature sensor (48) are placed at opposed side surfaces in the pot (41) that correspond to the short sides of an elongated roughly rectangular planar shape of the pot (41). An exposed state of the heater (42) from the water in the pot (41) is judged by the water level sensor (43) and the temperature sensor (48).