To provide a keyboard base for a large-sized display device which makes it easy to place a keyboard mount at a position where the screen is not covered.

The base of an arm 2 formed of an L-shaped round rod member is fitted to the flank of a device main body 1 rotatably on its vertical axis. To the tip side of the arm 2, the keyboard mount 3 is fitted rotatably on the horizontal axis of the flank of the device main body 1. A stopper mechanism 5 is provided atop of the arm 2 and the rotational position of the keyboard mount 3 on the arm 2 can be fixed freely at any angle. The keyboard mount 3 can be installed at an arbitrary angle to either the right or the left of the device body 1 and stored at a position where the keyboard mount is not an obstacle by entirely being turned over when not necessary.