A wireless communication device (102, 103) comprising: a transmitter/receiver configured to perform wireless communication including carrier sense; a determiner, a controller, and a power supply including an internal battery, and configured to supply power to the wireless communication device (102, 103), wherein a sleep mode is provided for the wireless communication device (102, 103),and the controller is further configured to reduce, in the sleep mode, consumption of power of the power supply, and to shut down at least power supply from the power supply to the transmitter/receiver; characterized by a counter configured to count the number of carrier sense executions, and the number of times of erroneous carrier sense in which in the carrier sense, a demodulated signal obtained by demodulation of a received signal received via the transmitter/receiver is determined not to be a signal addressed to the wireless communication device (102, 103), wherein when a ratio of the number of times of the erroneous carrier sense to the number of carrier sense executions is lower than a predetermined reference ratio for determination, the determiner determines that an abnormal situation caused by noise has not occurred in the carrier sense, whereas when the ratio of the number of times of the erroneous carrier sense to the number of carrier sense executions is higher than or equal to the predetermined reference ratio for determination, the determiner determines that the abnormal situation caused by noise has occurred in the carrier sense, wherein the controller is configured to transition to the sleep mode when the determiner determines that an abnormal situation caused by noise has occurred in the carrier sense; and a display configured to display alert information when the determiner determines that the abnormal situation caused by noise has occurred in the carrier sense, wherein the determination by the determiner is executed when the number of carrier sense executions is greater than or equal to a reference value for determination. a transmitter/receiver configured to perform wireless communication including carrier sense; a determiner, a controller, and a power supply including an internal battery, and configured to supply power to the wireless communication device (102, 103), wherein a sleep mode is provided for the wireless communication device (102, 103),and the controller is further configured to reduce, in the sleep mode, consumption of power of the power supply, and to shut down at least power supply from the power supply to the transmitter/receiver; characterized by a counter configured to count the number of carrier sense executions, and the number of times of erroneous carrier sense in which in the carrier sense, a demodulated signal obtained by demodulation of a received signal received via the transmitter/receiver is determined not to be a signal addressed to the wireless communication device (102, 103), wherein when a ratio of the number of times of the erroneous carrier sense to the number of carrier sense executions is lower than a predetermined reference ratio for determination, the determiner determines that an abnormal situation caused by noise has not occurred in the carrier sense, whereas when the ratio of the number of times of the erroneous carrier sense to the number of carrier sense executions is higher than or equal to the predetermined reference ratio for determination, the determiner determines that the abnormal situation caused by noise has occurred in the carrier sense, wherein the controller is configured to transition to the sleep mode when the determiner determines that an abnormal situation caused by noise has occurred in the carrier sense; and a display configured to display alert information when the determiner determines that the abnormal situation caused by noise has occurred in the carrier sense, wherein the determination by the determiner is executed when the number of carrier sense executions is greater than or equal to a reference value for determination.