STEAM GENERATOR

PROBLEM TO BE SOLVED: To provide a steam generator capable of stably supplying water.SOLUTION: A steam generator 1 includes a tank part 2 having an evaporation tank 21 and a water header 22, a spray nozzle 23 arranged in an inside of the evaporation tank 21, a spray water supply line L4 for supplying water in the water header 22 to the spray nozzle 23, a spray water pump 7, a make-up water line L7 for supplying make-up water to the water header 22, a make-up water pump 8, a water level detection part 27 for detecting a water level of the water header 22, and a control part 90. The control part 90 includes a first initial control part 92 which drives the make-up water pump 8 until the water level of the water header 22 reaches a first water level when the water level of the water header 22 is determined to be less than the first water level in initial water supply, continues driving of the make-up water pump 8 for first time T1 after the water level reaches the first water level, and stops driving of the make-up water pump 8 and drives the spray water pump 7 when the first time T1 is elapsed after the water level reaches the first water level.