To secure safety by relaxing unnatural feeling and impact for an occupant when the body of the occupant hits on an operating knob, to enhance habitability, and to allow an aged person or a handicapped person to easily operate a releasing mechanism.

This releasing mechanism is used for a locking device of a vehicle seat 31. The mechanism includes a release lever 11 arranged in the seat 31 to perform a releasing operation of the locking device of the seat 31, a release cable 12 with one end connected to the release lever 11, and the operating knob 15 having a size to be stored in the palm of a hand, formed into a spherical shape or a substantially spherical shape, arranged in a cavity 14 of the surface 32 at a proper portion of the seat 31 and connected to the other end of the release cable 12.