A mobile electronic device is provided. The mobile electronic device includes at least one processor, a display module electrically connected with the at least one processor, a communication module electrically connected with the at least one processor, a portable electronic device housing configured to house at least a part of the display module, the at least one processor, and the communication module, and a Heart Rate (HR) sensor (e.g., a Heart Rate Monitor (HRM) sensor) which is placed on one surface of the housing and has at least its part exposed to an outside, and which is electrically connected with the at least one processor.
