A separator includes a support formed in a grid, and a porous ion migration inhibition layer with which the grid of the support is coated and which has a plurality of pores formed therein, wherein each of the plurality of pores of the porous ion migration inhibition layer is formed to have a size smaller than the size of an electromigration-promoting ion contained in an electrolyte, whereby the electromigration-promoting ion does not pass through the porous ion migration inhibition layer. In addition, potassium is prevented from migrating to the carbon layer, thereby preventing potassium hydroxide from being precipitated even when oxygen is moved to a positive electrode side during charging. Furthermore, when the separator is applied to a separator of an alkaline battery, potassium hydroxide may be prevented from being precipitated during charging, thereby achieving an effect that an alkaline primary battery can be used as a secondary battery.