Abstract: Disclosed is a vehicular environment estimation device capable of accurately estimating a travel environment around own vehicle on the basis of a predicted route of a mobile object or the like, which is moving in a blind area. A vehicular environment estimation device that is mounted in the own vehicle detects a behavior of another vehicle in the vicinity of the own vehicle, and estimates a travel environment, which affects the traveling of another vehicle, on the basis of the behavior of another vehicle. For example, the presence of another vehicle, which is traveling in a blind area, is estimated on the basis of the behavior of another vehicle. Therefore, it is possible to estimate a vehicle travel environment that cannot be recognized by the own vehicle but can be recognized by another vehicle in the vicinity of the own vehicle.