An elastic fastener 1 comprises a hollow tubular portion 7, an internally threaded portion 2 provided at one of the ends of the tubular portion 7, and a flange 9 formed at the other end of the tubular portion 7. The tubular portion 7 and the flange 9 are integrally formed of an elastomeric material, such as a styrene-based elastomer, a polyamide-based elastomer and a polyester-based elastomer. The internally threaded portion 2 is formed of a rigid resin material such as a polycarbonate resin. The internally threaded portion 2 is integrally fixed to the tubular portion 7 in a hole of the tubular portion.