The principal object of the invention is to provide a lithium salt having excellent ion conductivity. The invention solves the problem by providing a lithium salt having a structure represented by the general formula (1): in which “M” represents B, Si, Ge, P, As or Sb; “X” represents the valence of “M”; “R1” represents —CmH2m— whereupon “m” is an integer of 1 to 4; “R2” represents —CkH2k+1 whereupon “k” is an integer of 1 to 8; and “n” represents 0 to 12.