A binder and a slurry suitable for use in the production of an electrode in a sulfide-based solid-state battery. The binder contains sulfide-based solid electrolyte particles, and is a fluorine-containing elastomer in which resin end functional groups satisfy: 0.01≤([—CH2OH]+[—COOH])/([—CH3]+[—CF2H]+[—CH2OH]+[—CH2I]+[—OC(O)RH]+[—COOH]≤0.25 where R represents an alkyl group with 1 to 20 carbon atoms. Also disclosed is an electrode including an electrode active material layer formed using the slurry and a lithium-ion secondary solid state battery including the electrode.