Abstract: In the chemical fiber industry, tantalum is considered as an ideal material to replace gold-platinum alloys in the manufacture of microporous ultrathin devices. However, the microporous ultrathin devices made of tantalum are easily scratched and deformed due to their low hardness and strength. Two methods of traditional direct current plasma nitriding（DCPN） and active screen plasma nitriding（ASPN） were used to improve the strength and toughness of microporous ultrathin devices made of tantalum. The results show that the hardening effect of DCPN is more obvious than that of ASPN. The ASPN-treated samples with nitriding temperature of 680℃ is increased to 394.7 HV in surface hardness, no cracks appears in the fracture toughness measured by the indentation method, and the surface morphology is good after nitriding, indicating that its comprehensive properties are optimal.