An electronic device includes a housing, a display device exposed through a first part of the housing, a recess formed in a second part of the housing, a receptacle formed in the recess, a plurality of conductive contacts disposed inside the receptacle and including a first contact, a first circuit that supplies and/or receives a current of a first level or larger to and/or from the first contact when an external connector is inserted into the receptacle, a first switching device that electrically connects the first circuit with the first contact or to interrupt a connection between the first circuit and the first contact, a second circuit that detects existence of a foreign object contacting the first contact while the external connector is inserted into the receptacle and a control circuit that controls the first switching device based at least in part on information regarding the detected existence of the foreign object.