An electronic device is provided. The electronic device includes a housing including a front surface, a rear surface, and a side surface which at least partially surrounds a space between the front surface and the rear surface, a first antenna disposed in the space, a second antenna disposed substantially in parallel with the rear surface in the space and formed in a coil shape, a conductor spaced a predetermined distance apart from a partial region of the second antenna substantially in parallel therewith and at least partially overlapping the partial region, a sensor electrically connected to the conductor, a communication circuit electrically connected to the first antenna, and a processor electrically connected to the sensor and the communication circuit, and the processor is configured to acquire a capacitance value related to the conductor, and reduce an intensity of a signal outputted through the first antenna according to the acquired capacitance value.