I really enjoy 1950's science fiction but this was hard to watch. Actually, John Agar (Dr. Roger) and Hugh Beaumont (Dr. Jud) made a relatively credible team of scientists. However, the third co-hort, Professor Lafarge, was one of the most helpless characters I think I've ever seen in one of these movies. First off, he's old and he can't keep up. He's also one of the biggest chickens in the history of science. Lafarge practically gets everyone killed numerous times. I know that gives away part of the story but believe me, if you watch this you'll want Lafarge dead anyway.
The underground civilization is actually called Sumerians. The mole people seem to be slaves to the Sumerians, but why they put up with the pasty white mushroom eaters, I do not know. The mole people are actually almost secondary characters which is very strange.
The hardest thing to take about this movie was how corny it was. The ancient Sumerians could barely get out of their own way. It's not even conceivable they could have survived underground for so many years.
The sets look cheesy, the matte paintings are the worst I've ever seen and Alan Napier makes an awful high priest. The ending is also totally ridiculous. Don't bother with "The Mole People" unless you're a John Agar fan or something.