Provided is an installation structure of a heat accumulator for a vehicle, provided on a back surface side of a bumper beam of the vehicle in the front portion of the vehicle and accumulates heat by storing a refrigerant. The bumper beam extends in the left-right direction of the vehicle and has a height dimension A in the vertical direction orthogonal to the length direction. The heat accumulator extends along the length direction of the bumper beam in a state of being close to a back surface of the bumper beam, and has a height dimension B in the vertical direction orthogonal to the length direction. The bumper beam and the heat accumulator are arranged with centers in the vertical direction coinciding with each other in the front-rear direction, and the height dimension B is set to A≤B≤1.6A with respect to the height dimension A.