A wristwatch (10, 10'), comprising a housing, a bottom cover, and a top cover, the housing made of a metal material, the top cover made of a non-metal material, the wristwatch (10, 10') further comprising: a short distance communication module disposed inside the housing, configured to carry out short distance communication with an external device, the short distance communication module comprising: a coil configured to transmit electromagnetic signals; a security chip configured to interpret the electromagnetic signals transmitted by the coil to carry out the short distance communication with the external device; an amplifier disposed between the coil and the security chip, configured to increase magnitude of the electromagnetic signals transmitted by the coil to extend signal sensing distance, characterized in that the short distance communication module further comprises: a transparent conductive film disposed on the top cover, configured to receive a user operation and generate a detecting signal correspondingly, wherein the transparent conductive film comprises a plurality of conductive wires that are interlaced with each other to construct a plurality of conductive units, and the detecting signal corresponds to an integral effect of electrical signal changes of all of the conductive units; and a controller coupled to the transparent conductive film and the amplifier, configured to receive the detecting signal and determine a gain of the amplifier according to the detecting signal, wherein based on the gain determined by the controller, the amplifier adjusts the magnitude of the electromagnetic signals transmitted by the coil to adjust the signal sensing distance. a coil configured to transmit electromagnetic signals; a security chip configured to interpret the electromagnetic signals transmitted by the coil to carry out the short distance communication with the external device; an amplifier disposed between the coil and the security chip, configured to increase magnitude of the electromagnetic signals transmitted by the coil to extend signal sensing distance, characterized in that the short distance communication module further comprises: a transparent conductive film disposed on the top cover, configured to receive a user operation and generate a detecting signal correspondingly, wherein the transparent conductive film comprises a plurality of conductive wires that are interlaced with each other to construct a plurality of conductive units, and the detecting signal corresponds to an integral effect of electrical signal changes of all of the conductive units; and a controller coupled to the transparent conductive film and the amplifier, configured to receive the detecting signal and determine a gain of the amplifier according to the detecting signal, wherein based on the gain determined by the controller, the amplifier adjusts the magnitude of the electromagnetic signals transmitted by the coil to adjust the signal sensing distance. a transparent conductive film disposed on the top cover, configured to receive a user operation and generate a detecting signal correspondingly, wherein the transparent conductive film comprises a plurality of conductive wires that are interlaced with each other to construct a plurality of conductive units, and the detecting signal corresponds to an integral effect of electrical signal changes of all of the conductive units; and a controller coupled to the transparent conductive film and the amplifier, configured to receive the detecting signal and determine a gain of the amplifier according to the detecting signal, wherein based on the gain determined by the controller, the amplifier adjusts the magnitude of the electromagnetic signals transmitted by the coil to adjust the signal sensing distance.