PROBLEM TO BE SOLVED: To provide a seat with a wakefulness maintenance device which can notify a seated person and a surrounding person of normal operation of the wakefulness maintenance device in a recognizable way.SOLUTION: A seat S provided with a wakefulness maintenance device U includes a respiration sensor U3 which detects a respiration signal of a seated person, a vibration unit U4 which provides vibration force to the seated person based on a detection result of the respiration sensor U3, and an operation indication part U6 which indicates that the wakefulness maintenance device U is operating or being stopped. The operation indication part U6 is mounted in a position which is visible from an external when the seated person takes a seat, for example an upper end part of a backrest part 2.SELECTED DRAWING: Figure 1
