All solid battery

An all solid battery comprising:

• a solid electrolyte layer that includes a first solid electrolyte;
• a positive electrode layer that is provided on a first main face of the solid electrolyte layer and includes a positive electrode active material and a second solid electrolyte;
• and
• a negative electrode layer that is provided on a second main face of the solid electrolyte layer and includes a negative electrode active material and a third solid electrolyte,
• wherein, in at least one of the positive electrode layer or the negative electrode layer, an average grain size of the second solid electrolyte or the third solid electrolyte is 2.5 μm or less, and an average grain size ratio of an average rain size of the positive electrode active material to an average grain size of the second solid electrolyte or an average grain size ratio of the negative electrode active material to an average grain size of the third solid electrolyte is 0.4 or more and 10 or less.