An input apparatus includes a profile key, a hot key, and a key for selectively inputting a character and a computer-game operating action. The profile key corresponds to a default profile including an extension code for the key to input the computer-game operating action. The hot key is configured to selectively switch the key to input the character and the computer-game operating action. When the profile key is actuated and the hot key is at a first status, the input apparatus outputs the extension code so that the key inputs the computer-game operating action. When the hot key is at a second status, the input apparatus outputs a standard key code so that the key inputs the character. A method of configuring the key as a hot key of a computer game is also provided.