To provide a protective barrier which is capable of absorbing sufficiently an impact of a rider or the like and has fire retardance.

The protective barrier 1 consists of a urethane foam 10 and a fire-retardant cover 20 covering the urethane foam 10. In the urethane foam 10, a cavity part is formed by a through hole 12 and a groove 15. The cover 20 formed of a fire-retardant material has flaps 31 provided in extension from a pair of longitudinal corner edges and each flap 31 is provided with a flat fastener 32. In the vicinity of a pair of the remaining longitudinal corner edges, a flat fastener 33 is provided on each lengthwise side 21 of the cover 20.