Occupant protection device

An occupant protection device that is mounted on a seat of a vehicle to enable protection of an occupant seated on the seat,

• wherein
• the occupant protection device comprising:
• a placement surface portion disposed on a seat portion of the seat and configured to allow the occupant to be placed on the placement surface portion to be able to support a region on a lower surface side at least around front ends of thighs of the seated occupant;
• two shoulder restraint belts extending from vicinities of left and right edges at an upper end of a backrest portion of the seat, disposed and configured to pass in front of left and right shoulders of the occupant, and having distal ends coupled to vicinities of left and right edges at a front end of the placement surface portion;
• at least one placement surface portion-side belt configured to be able to be unreeled by an unreeling mechanism disposed behind the seat and having a distal end coupled to a vicinity of a rear end of the placement surface portion;
• and
• a retractor disposed at a position behind the seat to enable unreeling of each of the shoulder restraint belts, and configured to be able to reel each of the shoulder restraint belts upon detection of an impact force applied from a front of the occupant.