A foldable electronic device is provided. The foldable electronic device includes a first housing, a second housing rotatably coupled to the first housing, at least one antenna disposed in at least one of the first housing or the second housing, a first grip sensor disposed in the first housing, a second grip sensor disposed in the second housing, and at least one processor. The at least one processor is configured to obtain a first detection value through the first grip sensor, obtain a second detection value through the second grip sensor, and decrease the strength of a signal output from the at least one antenna based on the first detection value and the second detection value.