To provide a device in which an effective pressure is relieved by a simple device and a seat belt is completely accommodated in a belt device at the time of releasing an installment though tension presses a chest portion of an occupant and the occupant sometimes feels a fatigue when the occupant of a car wears the seat belt.

An engagement member is pivotally supported with a guide member 2 having a guide groove of a rectangular cross section at an angle- adjustable. A seat belt B is inserted in the guide member 2 and the guide member 2 is engaged with a turn buckle T of the seat belt B. A tip end of the guide member 2 extends from above shoulder of a wearing person to a slightly forward direction. Therefore, the seat belt B is derived to the position in a straight line, is descended while maintaining an appropriate space from a chest portion of the wear person and is engaged with a side hook. Thereby, an oppression to the chest portion is solved.