According to various embodiments, an electronic device comprises: a housing including a first surface, a second surface facing in the opposite direction of the first surface, and side surfaces that surround at least a part of a space between the first surface and the second surface; a first sensor and a second sensor which are disposed in the housing or exposed through at least one surface; a communication circuit disposed in the housing; an antenna radiator electrically connected with the communication circuit; and a control circuit electrically connected with at least one of the first and second sensors, and the communication circuit, wherein the control circuit is configured to: transmit or receive, to or from an external device, a first signal output from the communication circuit, using the antenna radiator; detect, using the first sensor, whether an external object has approached within a predetermined distance at least a part of the antenna radiator to generate a second signal; detect, using the second sensor, an orientation of the electronic device to generate a third signal; and decrease the strength of the first signal, based on at least a part of the generated second signal and third signal.