Male fertility decreases with ages, above all after 40 years old. However, this decrease is not as pronounced as it is in women. It is characterized by a progressive reduction in seminal volume, sperm concentration etc. It is also possible to see genetic alterations in the DNA of the sperm. In spite of this, there are men who continue to be fertile and have had children after the age of 50 or 60.
You can read more about this in the following article: The andropause - male menopause.