The comic is one of only nine left from the first lot printed way back in 1938.
The owner, who's in his 70s, has kept it in his house in Lincoln ever since his mum gave it to him.
Regular bag changes
Every time he had a clean-up he would take it out of the plastic bag and put it in a new one.
Although Dennis the Menace is the Beano's most popular character now, he didn't appear in the first edition.
The world record price for a first issue Beano is £6,820.