An aircraft seat unit comprising: a first seat; a second seat; an intermediate portion disposed between the first seat and the second seat; and a wall portion adjacent to the intermediate portion; wherein: an axis line of the first seat and an axis line of the second seat are respectively disposed at angles that are oriented in mutually opposite directions with respect to a traveling direction; the intermediate portion is disposed in a space between the first seat and the second seat and is capable of supporting a load of a restrained body placed thereon; and the wall portion includes a wall connection portion configured to be detachably connected to a device" connection portion of a restraining device (30, 40, 50) that restrains the restrained body placed on the intermediate portion characterized in that: the intermediate portion includes two pedestals (15a, 15b) able to be fixed to a floor, a support portion capable of sliding in a guide between the pedestals (15a, 15b), in a vertical direction with respect to the pedestals, and a partition plate capable of sliding in a vertical direction with respect to the support portion, such that when the support portion and the partition plate are raised, an upper end of the partition plate is above an eye level of a passenger seated in the first seat or the second seat, and when the support portion and the partition plate are lowered, a height of an upper surface of the pedestals and the support portion and a height of the upper end of the partition plate substantially coincide, and the restraining device can be connected to the wall portion. a first seat; a second seat; an intermediate portion disposed between the first seat and the second seat; and a wall portion adjacent to the intermediate portion; wherein: an axis line of the first seat and an axis line of the second seat are respectively disposed at angles that are oriented in mutually opposite directions with respect to a traveling direction; the intermediate portion is disposed in a space between the first seat and the second seat and is capable of supporting a load of a restrained body placed thereon; and the wall portion includes a wall connection portion configured to be detachably connected to a device" an axis line of the first seat and an axis line of the second seat are respectively disposed at angles that are oriented in mutually opposite directions with respect to a traveling direction; the intermediate portion is disposed in a space between the first seat and the second seat and is capable of supporting a load of a restrained body placed thereon; and the wall portion includes a wall connection portion configured to be detachably connected to a device" connection portion of a restraining device (30, 40, 50) that restrains the restrained body placed on the intermediate portion characterized in that: the intermediate portion includes two pedestals (15a, 15b) able to be fixed to a floor, a support portion capable of sliding in a guide between the pedestals (15a, 15b), in a vertical direction with respect to the pedestals, and a partition plate capable of sliding in a vertical direction with respect to the support portion, such that when the support portion and the partition plate are raised, an upper end of the partition plate is above an eye level of a passenger seated in the first seat or the second seat, and when the support portion and the partition plate are lowered, a height of an upper surface of the pedestals and the support portion and a height of the upper end of the partition plate substantially coincide, and the restraining device can be connected to the wall portion. the intermediate portion includes two pedestals (15a, 15b) able to be fixed to a floor, a support portion capable of sliding in a guide between the pedestals (15a, 15b), in a vertical direction with respect to the pedestals, and a partition plate capable of sliding in a vertical direction with respect to the support portion, such that when the support portion and the partition plate are raised, an upper end of the partition plate is above an eye level of a passenger seated in the first seat or the second seat, and when the support portion and the partition plate are lowered, a height of an upper surface of the pedestals and the support portion and a height of the upper end of the partition plate substantially coincide, and the restraining device can be connected to the wall portion.