The invention provides a heating cooker, capable of realizing heating cooking without disproportion heating based on uniform heating in the box, in a heating cooking wherein the temperature in the box is set to below100 DEG C. The heating cooker includes an inside heating mechanism, a water vapor generating mechanism and a control section for controlling them. The heating steps controlled by the control section includes a first step when the temperature inside the box raises until it reaches the setting value; and a second step of maintaining the setting value in the box, in the second step, the supply power input to the water vapor generating mechanism is set to be larger than the supply power input to the inside heating mechanism.