An induction heating cooker comprising: a top panel for mounting a cooking container; a heating coil provided under the top panel, for heating the cooking container by induction; an inverter for supplying a high-frequency current to the heating coil; an electrode provided on a back surface of the top panel adjacent to a periphery of the heating coil; an electrostatic capacitance detecting portion for supplying a high-frequency signal to the electrode and detecting electrostatic capacitance of the electrode; a memory portion for storing the detected electrostatic capacitance as a reference value; and a control portion for controlling the inverter such that heating output of the inverter reaches a first set value, characterized in that the induction heating cooker further comprises a boiling over detecting portion for executing a reference value updating process to store the electrostatic capacitance in the memory portion as the reference value when the electrostatic capacitance of the electrode satisfies a predetermined condition, and executing an output controlling action to reduce the heating output of the inverter to a predetermined second set value or stop a heating action, after a change amount of the electrostatic capacitance of the electrode with respect to the reference value reaches an output reducing threshold value or more, wherein the boiling over detecting portion stops the heating action or reduces the heating output to a third set value lower than the second set value when a change rate of the detected electrostatic capacitance reaches a predetermined change rate or more, and returns the heating output to the first set value when the change rate of the detected electrostatic capacitance is less than the predetermined change rate, during a change rate detecting period including the time when the change amount of the electrostatic capacitance of the electrode with respect to the reference value reaches the output reducing threshold value or more. a top panel for mounting a cooking container; a heating coil provided under the top panel, for heating the cooking container by induction; an inverter for supplying a high-frequency current to the heating coil; an electrode provided on a back surface of the top panel adjacent to a periphery of the heating coil; an electrostatic capacitance detecting portion for supplying a high-frequency signal to the electrode and detecting electrostatic capacitance of the electrode; a memory portion for storing the detected electrostatic capacitance as a reference value; and a control portion for controlling the inverter such that heating output of the inverter reaches a first set value, characterized in that the induction heating cooker further comprises a boiling over detecting portion for executing a reference value updating process to store the electrostatic capacitance in the memory portion as the reference value when the electrostatic capacitance of the electrode satisfies a predetermined condition, and executing an output controlling action to reduce the heating output of the inverter to a predetermined second set value or stop a heating action, after a change amount of the electrostatic capacitance of the electrode with respect to the reference value reaches an output reducing threshold value or more, wherein the boiling over detecting portion stops the heating action or reduces the heating output to a third set value lower than the second set value when a change rate of the detected electrostatic capacitance reaches a predetermined change rate or more, and returns the heating output to the first set value when the change rate of the detected electrostatic capacitance is less than the predetermined change rate, during a change rate detecting period including the time when the change amount of the electrostatic capacitance of the electrode with respect to the reference value reaches the output reducing threshold value or more.