Abstract: The present invention relates to a portable electronic device which can be switched between a first mode and a second mode. The portable electronic device comprises a first sensor to detect a touch on the portable electronic device and generate a first signal based on such touch, a second sensor to detect a movement of the portable electronic device and generate a second signal based on such movement, and a processing unit which electrically connects the first sensor and the second sensor. When the portable electronic device is in the first mode, the processing unit switches the portable electronic device to the second mode based on the first and second signals. In addition, the present invention provides a mode switching method that enables the portable electronic device to determine whether to enter or exit from the sleep mode.