Various embodiments provide an electronic device and a method, the device comprising: a capacitive sensor, a heart rate sensor including at least one light-emitting unit, a first light receiving unit, and a second light receiving unit; and a processor, wherein the processor is configured to: measure capacitance for a user wearing the electronic device by using the capacitive sensor; emit light by using the light-emitting unit according to the capacitance; measure a first amount of light which is said light reflected by the user's body tissue through the first light receiving unit, and a second amount of light which is said light reflected by the body tissue through the second light receiving unit; determine that the electronic device is worn by the user when at least one amount of light of the first amount of light and the second amount of light satisfies an amount of light in a specified range; and determine that the electronic device is detached from the user when the first amount of light and the second amount of light do not satisfy the amount of light in the specified range. Also, other embodiments are possible.