Willy Millowitsch as Hubsi Kleiner

Harald Juhnke as Horst Itzenblitz

Walter Gross as Siegfried Zackel

Viktor Staal as Geologe Dr. Ebert

Willy Reichert as Geologe Dr. Rothnagel

Magrit Aust as Mia Schöner

Teddy Parker as Pianist Toni

Gernot Duda as Bohrtruppleiter

Franz Schneider as Postenkommandant