An all-solid-state battery system comprising an all-solid-state battery comprising a positive electrode active material layer, a solid electrolyte layer, and a negative electrode active material layer, and a control device configured to control a charge-discharge voltage during use of the all-solid-state battery. The negative electrode active material layer includes alloy negative electrode active material particles. The amorphization degree of the alloy negative electrode active material particles is in the range of 27.8% to 82.8% and a ratio Z/W is in the range of 0.32 to 0.60, where Z is a controlled discharge capacity of the all-solid-state battery, and W is a theoretical capacity of the alloy negative electrode active material particles × a total weight of the alloy negative electrode active material particles × the amorphization degree.