To easily prevent any inappropriate user from sitting in a reserved seat.

This seat management method includes: a step for collecting entry ticket information written in an entry ticket for entering a movie theater 11 from an entering/leaving management system 7; a step for making available an entry seat shown by the entry ticket information among a plurality of seats 8-1 to 8-n; a step for collecting leaving ticket information written in a leaving ticket 5 for leaving the movie theater 11 from the entering/leaving management system 7; a step for making unavailable a leaving seat shown by the leaving ticket information among the plurality of seats 8-1 to 8-n; a step for collecting seating ticket information written in a seating ticket arranged in a seating seat among the plurality of seats 8-1 to 8-n; and a step for making an output device arranged in the seating seat guide whether or not the seating seat is made to correspond to the seating ticket information.