The aircraft seat unit includes a first seat 13, a second seat 14, an intermediate portion 15 disposed between the first seat 13 and the second seat 14, and a front wall 11 adjacent to the intermediate portion 15. An axis line X1 of the first seat 13 and an axis line X2 of the second seat 14 are respectively disposed at angles that are oriented in mutually opposite directions with respect to a traveling direction. The intermediate portion 15 is disposed in a space between the first set and the second seat and is capable of supporting a load of a bassinet 30 placed thereon. The front wall 11 includes engagement holes 11e that detachably engage with engagement portions 32 of the bassinet 30.