The utility model provides a restricting devices that can further reduce equipment man -hour of buffer unit. This restricting devices possesses: the backstop part that can change for the posture of guide rail, and be fixed in the backstop part and contact and restrict the buffer unit of the posture of backstop part with the guide rail along with the posture change of this backstop part, be formed with the width direction outside open -ended installation concave part to the vehicle at the backstop part, the messenger should install concave part open derivation downwards mouth, the anti -separation piece who sets up is stuck out to open end at the installation concave part towards the top, and towards the outstanding gomphosis piece that sets up in below, the buffer unit has the fixed part of embedding installation concave part, from the backstop part downwards outstanding and can with the elasticity portion of guide rail contact, it derives mouthful and with the connecting portion that couple together between fixed part and the elasticity portion to pass, the portion is formed with sunkenly and supply the gomphosis hole of gomphosis piece embedding downwards in elasticity.