A tilt structure to be provided allows the tilt of a console to be changed through simple motion and has a simple configuration. A link mechanism (a mechanism similar to a slider crank mechanism) composed of three turning pairs and one sliding pair is formed using a first frame 20, a second frame 25, a slider 37, and a connection member 30. The tilt structure includes a control member 40 or 47 for fixing or unfixing the tilt of the second frame 25. The control member 40 or 47 is provided controllably in order to lock or unlock motion of the link mechanism.