A battery cover device for a portable terminal is provided. The battery cover device includes a battery recess formed on a surface of the terminal, a cover plate adapted to attach to and detach from a surface of the terminal to cover the battery recess, and a push rod adapted to protract to and retract from a surface of the terminal. The push rod receives elastic force to protrude from a surface of the terminal and release the cover plate from the terminal. The battery cover device is advantageous in that the cover plate can be easily released by using the push rod or elastic piece, and a battery pack can be easily mounted on a slim terminal.