A communication terminal and an antenna apparatus of the communication terminal are provided. The communication terminal includes a body having a circuit board, an antenna element which is mounted inside the body and connected electrically to the circuit board and, when electric current is supplied via a main plate, resonant in a resonant frequency band for transmitting and receiving signals, and a metal case having an antenna pattern which is coupled to an edge of the body to be resonant and, when the antenna element is resonant, in the resonant frequency band for supporting operation of the antenna element.