According to one embodiment, an electronic device includes: a casing comprising a display thereto, the casing being configured to house therein an electric component configured to generate heat; a wearing member configured to be wrapped around an arm of a human body to cause the casing to be worn on the arm; a plurality of electrodes configured to face, in a state that the casing is worn on an arm, a side of the arm; an impedance measurement module configured to measure impedance between two of the electrodes; and a controller configured to control the electric component so that when the impedance obtained in the impedance measurement module is lower than a threshold, an amount of the heat generated by the electric component becomes small compared with a case that the impedance is higher than the threshold.