This study was carried out to investigate the antioxidant activity and changes in major functional components of fermented Gastrodia elata Blume. Fermented G. elata Blume powder by Phellinus linteus repeated thrice ($3^{rd}$ FGP) showed more DPPH radical scavenging activity than a non-fermented G. elata Blume powder (NFGP), and once fermented G. elata Blume powder ($1^{st}$ FGP) at a concentration of 500 and 1,000 ppm. Free radical scavenging activity of $3^{rd}$ FGP was similar to that of BHA at a dose of 1,000 ppm. Moreover, the ABTS radical scavenging activity of the $3^{rd}$ FGP increased compared to NFGP and $1^{st}$ FGP at a concentration of 31.25 ppm. Total polyphenols and flavonoid contents were increased as fermentation progressed. Ergothioneine content was increased more than 8 times in the $1^{st}$ FGP, 3 times in the $3^{rd}$ FGP, respectively than NFGP. In conclusion, this study indicated that the antioxidant activity and functional component contents of G. elata Blume were increased depending on the fermentation number.