A seating determination apparatus includes a transition processing unit 29 configured to make a transition of the state between a first seating determination state in which an airbag apparatus is brought into an operation-permitted state and the second seating determination state in which the airbag apparatus is in the operation-prohibited state when a transition condition on the basis of a magnitude relationship between a seat load and a preset threshold value is satisfied, and configured to prohibit the transition of the state between the first seating determination state and the second eating determination state when the direction of variation of the seat load is determined to have inverted before a predetermined time set in advance has elapsed from a time point when the transition condition is satisfied.