Provided is a planar inverted-F antenna (PIFA) which has a Co-Planar Waveguide (CPW) feeding structure and can be attached to a metal surface, and an RFID tag using the same. The PIFA includes a radiation patch layer; a Co-Planar Waveguide (CPW) feeding layer; a feeding probe; and a short-circuit. The CPW feeding layer includes a feeding means and a ground surface. The feeding probe electrically connects the radiation patch layer and the feeding means and provides a Radio Frequency (RF) signal to be radiated to the radiation patch layer. The short-circuiting means short-circuits the radiation patch layer and the ground surface through the dielectric layer. The PIFA can be applied to a passive RFID tag. Impedance matching between the antenna and the RFID chip is possible. Also, the PIFA can easily control resonant frequency of the antenna and reactance.