To attach a seat belt only by moving one hand from the left to the right or from the right to the left around a waist part by providing a lower winding device and respective stoppers restricting winding of the seat belt in a lower opening part in addition to an upper winding device in an upper opening part.

A seat belt device for an automobile is provided with an upper opening part 1 opened in a vehicle body C on the window side, a lower opening part 2 opened in the body C below the upper opening part 1, a seat belt 3 whose respective end sides are inserted through an upper hanging ring tool 1a and a lower hanging ring tool 2a, an upper winding device 4 winding the end side passed through the upper opening 1, a lower winding device 5 winding up the end side of the seat belt 3 passed through the lower opening part 2, a seat belt stopper 6 passed through the seat belt 3 freely slidably, a vehicle body side stopper 7 removably fitted in the seat belt side stopper 6 and arranged on the opposite side to the seat belt stopper 6 while putting a seat between them, and a stopper upper part 8 and a lower part 9 regulating the stopper 6 for the seat belt 3 to the upper opening part 1 and the lower opening part 2.