In a shielding state, a partition extends from an upper portion to a lower portion of a cabin in such a manner as to partition a space between a pair of opposing vehicle seats. In the case where the partition is in the shielding state during a collision of a vehicle, the partition is inflated in a vehicle longitudinal direction by gas supplied from an inflator that is actuated when a collision detection sensor detects the collision of the vehicle. That is, since the partition is inflated in the space between the pair of the vehicle seats without interfering with the vehicle seats, the partition can reliably restrain an occupant who receives a collision load and is thereby displaced in the vehicle longitudinal direction from the vehicle seat. In this way, it is possible to easily secure a private space in the cabin and to improve occupant restraint performance.