Solid electrolyte composition, solid electrolyte-containing sheet and all-solid secondary battery

A solid electrolyte composition containing an inorganic solid electrolyte (A) having conductivity of metal ions belonging to Group 1 or Group 2 of the Periodic Table and a binder (B), wherein the binder (B) is A solid electrolyte composition containing a polymer that satisfies the following condition (1) or (2), a solid electrolyte-containing sheet and an all-solid secondary battery, and a method for producing the solid electrolyte-containing sheet and the all-solid secondary battery. (Condition 1) Young's modulus 0.003 GPa or more and less than 0.2 GPa, breaking elongation 300 to 700% (Condition 2) Young's modulus 0.2 to 2 GPa, breaking elongation 10 to 1000%