To allow a third person outside a vehicle to visually recognize a generation place and a generation range of a warning region for which a no-entry warning is to be issued.

A vehicle warning device mounted on a vehicle 2 comprises: a warning region generation determination section 20 and a spray device 12. The warning region generation determination section 20 determines whether or not a warning region, for which a no-entry warning is to be issued to a third person outside the vehicle 2, is generated around the vehicle 2. The spray device 20 sprays particles having a predetermined reflection characteristic on the warning region when the warning region generation determination section 20 determines that the warning region is generated.