The WiFi apparatus for wireless Internet includes: a signal inputting unit including a plurality of input ports for inputting a plurality of mobile communication signals, respectively, and an input port for inputting an Ethernet signal; a signal converting unit for converting the inputted Ethernet signal into a plurality of WiFi signals; a signal coupling unit for coupling the plurality of inputted mobile communication signals to the plurality of WiFi signals converted by the signal converting unit, respectively; a signal outputting unit for outputting a plurality of coupled signals coupled by the signal coupling unit through a plurality of output ports, respectively; and a coupler for allowing each of signals outputted from the signal outputting unit to be split with different phase differences and to be outputted.