To perform a (game) input into a game input device by a non-contact.

In the game machine provided with a storing part into which a game program is incorporated, a game control part for advancing a game by the game program read from the storing part and a game input device connected electrically with the game control part, the game is characterized by constituting the game input device by a light, a camera and an image processing part connected electrically with the camera, photographing shadow of a specified portion of a game player generated by the light by the camera, forming first projection data based on the photographed data, photographing shadow of the specified portion of the game player generated by the light again after prescribed time, forming second projection data based on the photographed data, and detecting movement of the game player and transmitting the movement as a game input to the game control part by comparing the first projection data and second projection data by the image processing part.