An electronic device using a millimeter wave, according to various embodiments, includes a communication circuit and at least one processor. The at least one processor can be configured to: control the communication circuit so that a first millimeter wave signal is output at a first strength; use the communication circuit so that the first millimeter wave signal receives a first reflection signal reflected by an object; confirm whether the object is positioned within a first distance from the electronic device; determine the strength of a second millimeter wave signal to be a second strength corresponding to a second distance between the electronic device and the object, the second distance being shorter than the first distance; and control the communication circuit so that the second millimeter wave signal is output at the determined second strength.