There is provided an information input system enabling the realization of an input method easily understandable and operable by intuition. This information input system is provided with a camera 11 for picking up an image of a specified area including a fingertip OF of an operator and an input surface 17 as a photographed image, a contact discriminator 154 for discriminating whether or not the fingertip OF and the input surface 17 are in contact with each other by specifying the fingertip OF and the input surface 17 included in the photographed image, and a fingertip position detector 152 for detecting a relative position of the fingertip OF with respect to the input surface 17 when the contact discriminator 154 judges that the fingertip OF and the input surface 17 are in contact with each other.