WARNING DEVICE

Provided is a warning device that is highly effective in encouraging a driver to stop visually distracted driving. This warning device (12) comprises: a visually-distracted-driving determination means (52) that determines that a driver (100) is visually distracted if the direction (X) in which the driver (100) is looking is greater than or equal to a predetermined angle (TH¸1, TH¸2) with respect to the front of the driver (100); and a warning means (22a, 24) that issues a visual warning at a position visible to the driver (100) when it is determined by the visually-distracted-driving determination means (52) that the driver is visually distracted. The warning means (22a, 24) is arranged on (a) virtual boundary line(s) (62, 64) forming said predetermined angle (TH¸1, TH¸2) with the front of the driver (100) on the right and/or left side(s) thereof.