An apparatus is provided that warns a vehicle of a harsh braking-applied vehicle based on information sent from the harsh braking-applied vehicle. The apparatus includes a reception device, a position detection device, a forward side vehicle judgment device, and a warning device. The reception device receives the information indicating that harsh braking has been applied to the harsh braking-applied vehicle and information indicating a position of the harsh braking-applied vehicle. The position detection device detects a position of the vehicle to be warned, and the forward side vehicle judgment device determines if the harsh braking-applied vehicle is in front of the vehicle to be warned based on the positions of the harsh braking-applied vehicle and the vehicle to be warned. The warning device warns the vehicle to be warned when the harsh braking-applied vehicle is in front of the vehicle to be warned.