A collision mitigation apparatus is provided, which is installed in a vehicle and mitigates damage to the vehicle in occurrence of a collision. The apparatus includes an activation control section which detects an object positioned around the vehicle, and activates a collision mitigation part for mitigating damage to the vehicle in occurrence of a collision if a positional relationship between the vehicle and the object meets a predetermined activation condition, a type determining section which determines type of the object, the type being any one of a vehicle, a pedestrian and a roadside object, and an activation condition changing section which consolidates the activation condition compared to a case where the type of the object is not a roadside object, if the type of the object is a roadside object.