To provide a knife for eat and drink which can be welded integrally with a metallic grip part, has satisfactory corrosion resistance and can achieve hardness higher than a specified hardness value required as a high-quality knife.

This knife has the composition of ≤0.15wt.% C, 3.2-4.5wt.% Si, ≤2.0wt.% Mn, ≤0.04wt.% P, ≤0.03wt.% S, 6.0-7.8wt.% Ni, 13.0-17.0wt.% Cr, 0.8-2.0wt.% Mo, ≥0.1% N and the balace Fe. Then, this knife is constituted by integrally welding a blade part composed of austenite stainless steel, of which the Vickers hardness (Hv) is ≥450, and the metallic grip part.