The present invention pertains to an all-solid capacitor having a high capacitance and excellent frequency characteristics, the all-solid capacitor being miniaturizable. This all-solid capacitor includes an inorganic solid electrolyte and a pair of current collectors provided to sandwich the inorganic solid electrode, the inorganic solid electrolyte having a primary crystalline phase having a perovskite crystalline structure represented by general formula ABO3. A-site elements comprise two elements including Li and an element (M), which is at least one Group 2 element on the periodic table, and B-site elements comprise two elements including Ti and an element (M), which is at least one Group 5 element on the periodic table.