A user can simply select and set up resolution of a monitor display device 2 among the resolutions which the monitor display device 2 supports, according to his/her taste, only by operating a specific key such provided in the remote control 4. The resolution of the monitor display device 2 is changed responding to a number of pressing down of the specific key by the user. When a command is inputted once, the resolution of video signals outputted from the optical disc player 1 is changed to be the lowest level. When the command is inputted twice, the resolution of the video signals is changed to be the next level. When the specific key is pressed down furthermore while the monitor display device 2 displays the images at the highest resolution, the output of the video signals from the optical disc player 1 is stopped. When the specific key is pressed down furthermore, the video signals are outputted at the lowest resolution.