A battery pack installing a floor of a vehicle includes one or more battery cells, a battery pack case in which the one or more battery cells are disposed, and a cushioning member arranged to be sandwiched between the one or more battery cells and the floor or between the one or more battery cells and the battery pack case, by fixing the battery pack case to the floor. Then, the first cushioning member may be configured such that a first area farther from suspension mounts is configured to a first elastic modulus, and the second area closer to the suspension mounts than the first area is configured to a second elastic modulus lower than the first elastic modulus.