This application provides an electrochemical apparatus and an electronic apparatus. The electrochemical apparatus includes a positive electrode plate, where the positive electrode plate includes a positive electrode material layer, the positive electrode material layer includes a positive electrode active material, elements in the positive electrode active material include Li, Mn, Ni, Co, and Fe, and the positive electrode active material satisfies at least one of the following characteristics: (i) a ratio A of the number of Mn atoms to a total number of Ni, Co, and Fe atoms being 3.5 to 40; and (ii) a ratio B of the number of Li atoms to a total number of Mn, Ni, Co, and Fe atoms being 0.51 to 0.79. The elements in the positive electrode active material are controlled to satisfy the range of A and/or B, which helps to improve overall performance of the electrochemical apparatus.