PURPOSE: To provide a welding material which is suitable for the welding of the non-magnetic material for the cryogenic use, and can provide the weld metal of the excellent low temperature toughness while ensuring the strength of the base metal.

CONSTITUTION: The welding material is Ni-base alloy having a composition consisting of ≤0.025% C, ≤0.15% Si, ≤0.25% Mn, ≤0.010% P, ≤0.005% S, 30.0-45.0% Ni, 10.0-20.0% Cr, ≤2.0% Mo, 0.6-2.0% Ti, 1.5-3.0% Nb, ≤0.5% Al while satisfying the inequalities of 2.0%≤Ti+Nb≤4.0% and Ti+ Nb+15×Si≤5.0%, and the substantial balance Fe. This material is suitable for the welding of the non-magnetic structural material (A286 alloy, etc.) for cryogenic use such as the super-conductive generator and the fusion reactor.