An electronic device can include a housing including a first surface, a second surface, and a third surface, the first and second surface defining an electronic component mounting space and the second and third surface defining a pen mounting space adapted to receive an electronic pen; and a display and an ElectroMagnetic Resonance (EMR) sensor pad disposed in the electronic component mounting space. When the electronic pen is mounted in the pen mounting space, the EMR sensor pad may detect a resonance frequency of a coil body of the electronic pen.