To signal a danger to a user and people around him/her when necessary and help them avoid the danger by annexing a display device displaying by light to the board body of a ski, a snowboard, or the like, when vibration or impact acts thereon.

A board 1 such as a snowboard is made up of a board body 2 and a display device 3 annexed to the top face near the end thereof. The display device 3, a base plate 5 fastened to the board body 2 by an adhesive or a double-sided adhesive tape, and a display circuit 9 in which a battery 6 annexed to the base plate 5, a vibration sensor 7 and a display lamp 8 made up of a light-emitting diode or the like are connected in series. When the board 1 slides over snow, if a prescribed vibration or impact acts on the board body 2, the display lamp 8 is turned on by operating the vibration sensor 7 of the display device 3. Therefore, a user can avoid a danger by sliding over snow in a manner that prevents the display lamp 8 from turning on, and people around him can avoid the danger by watching the display lamp 8 turned on.