The invention concerns an absorbent article, such as a diaper, pant diaper, incontinence guard, panty liner, open diaper, belt diaper or the like. More specifically, the invention concerns a fastening device for an absorbent article having a receiving portion with an opening, and a tab element which is shaped so that it can be inserted into the opening of the receiving portion upon closing the article. It is characteristic of the invention that both the tab element and the receiving portion have fastening means. By the fact that both the receiving portion and the tab element have fastening means, a strong and stable connection is formed between the components of the fastening device.