Fe-based shape memory alloy and manufacturing method thereof

25 to 42 and atomic% of Mn, and 12 to 18 atomic% Al, and contains a 5 to 12 atomic% of Ni, Fe based shape memory alloy and the balance being Fe and unavoidable impurities, and 25 to 42 atom % and Mn of, and 12 to 18 atomic% Al, and contains a 5 to 12 atomic% of Ni, further 0.1 to 5 atomic% of Si, 0.1 to 5 atomic% of Ti, 0.1 to 5 atomic% of V 0.1-5 atomic% of Cr, 0.1 to 5 atomic% of Co, 0.1 to 5 atomic% of Cu, 0.1 to 5 atomic% of Mo, 0.1 to 5 atomic% of W, the 0.001 atomic% B and 0.001 at least one member selected from the group consisting of ~ 1 atom% of C contained 15 atomic% or less in total, Fe based shape memory alloy and the balance being Fe and unavoidable impurities.