It is intended to provide a food or a drink with a favorable flavor which has an acidic nature, contains protein and minerals, and has been stabilized in dispersion without showing any protein aggregation or the like even in the absence of a stabilizer. It is also intended to provide such an acidic protein food or drink which shows no protein aggregation even in the case of using not only minerals hardly soluble in aqueous media but also highly soluble minerals. By using an acid-soluble soybean protein, it is possible to provide an acidic mineral-containing food or drink which has a high stability without resort to a stabilizer as an essential component. Owing to the acidic nature, moreover, a product having a refreshing flavor, which is never achieved by neutral foods or drinks, can be prepared.