A liquid state detecting sensor includes: a state detecting element including a heating resistor; an energization unit; a first output acquiring unit; a reference acquiring unit; a first calculating unit; a state detecting unit; a second output acquiring unit; a second calculating unit; an excess-temperature-rise determining unit; and an energization terminating unit. The energization termination unit terminates energizing of the heating resistor by the energization unit before the end of a detection time period in response to a determination by the excessive-temperature-rise determining unit that an excessive temperature rise has occurred in the state detecting element.