The present invention provides an alkaline battery which has high reliability and high cost performance and does not cause an internal short circuit resulting from gel leakage even when the filling densities of the positive and negative electrodes are reduced. In the alkaline battery, a positive electrode 2 contains manganese dioxide as a positive electrode active material, a negative electrode 3 is a gel negative electrode containing zinc as a negative electrode active material, a filling density of manganese dioxide in the positive electrode 2 is in a range of 2.31 to 2.45 g/cm 3 , a filling density of zinc in the negative electrode 3 is in a range of 1.49 to 1.65 g/cm 3 , and a ratio (h1/h2) between a height of the positive electrode 2 (h1) and a height of the negative electrode 3 (h2) is in a range of 0.96 to 1.06.