Abstract: A wireless tap-off device capable of providing a wireless LAN service, which can allow a user to receive a wireless LAN service anywhere in the country through a tap-off device of an existing CATV network, is provided. The wireless tap-off device may include a cable modem which converts a CATV signal into an Ethernet signal, outputs the converted signal, converts an Ethernet signal into a CATV signal, and transmits the converted signal to a connector, an access point which converts an Ethernet signal applied from the cable modem into a wireless signal, transmits the converted signal to a computer device through an antenna in a wireless manner, converts a wireless signal applied from the computer device into an Ethernet signal, and provides the converted signal to the cable modem, a DC power supply, and a switching unit.