According to one aspect of the present invention, disclosed is an automatic calibration method for a calibration device connected to a camera that is disposed the end effector of a robot and to a robot controller for controlling the robot. The method comprises the steps of: acquiring, from the camera and the robot controller, a robot-based coordinate system and an image of a marker marked in the work area of the robot (wherein the acquired image and robot-based coordinate system are recorded while the end effector is moved to a plurality of sample coordinates); and estimating the position of a robot coordinate system-based marker by using the acquired image and robot-based coordinate system.