Disclosed is a martensitic stainless steel with excellent hardenability through the control of a component system. The martensitic stainless steel with excellent hardenability comprises, in percent by weight (wt %), 0.01 to 0.1% of C, 0.05 to 0.1% of Si, 0.05 to 1.0 of Mn, 11.0 to 14.0% of Cr, 0.05 to 1.0% of Ni, 0.05 to 2.0% of Cu, 0.04 to 0.08% of N, and the balance of Fe and inevitable impurities, and satisfies Formula (1). wherein Mn, Ni, and Cu denote contents (wt %) of elements, respectively.