Benoit, the head guard of Clouville Prison, prefers to be liked than feared. This basic principle transforms the jail-house into a joyful prison, where all the inmates live amicably together. Among them, various colorful characters : a farmer, a poacher, a distiller, a forger, two pickpockets, a safe-cracker, a gangster and... a good-looking guy who pleases Rosette, Benoit's daughter, well. But too much leniency takes its toll : after Vauclin, the gangster, manages to escape and a complaint is filed against "the deplorable disorder reigning in the joyful prison", Benoit is given early retirement. He will know how to take advantage of his new status live a joyful life with his wife, his daughter and André, his son in law, in fact the nice-looking young prisoner who, in the meantime, has been cleared of all charges.

Michel Simon
Benoit, chief guard

Ded Rysel
Auguste Tuboeuf, inmate farmer

Paulette Dubost
Justine Benoit

Lisette Lebon
Rosette Benoit

Michel Roux
André Chauvin

Christian Alers
Sub-prefect
Georges Baconnet
Ferdinand Bouchonnet
Francis Boyer

Henri Coutet
Gustave

Robert Dalban
Vauclin, inmate gangster
Paul Derly
Breton, safe-cracking inmate

Émile Genevois
'Petit Louis', burglar inmate
Marguerite Héliès
Sub-prefect

Jane Helly

Marcel Rouzé
Brigadier