Kenji Sahara as Shigeru Kawamura

Yumi Shirakawa as Kiyo

Akihiko Hirata as Professor Kyuichiro Kashiwagi

Minosuke Yamada as Mining Chief Osaki

Yoshifumi Tajima as Izeki

Akio Kobori as Police Chief Nishimura

Mitsuo Tsuda as Staff Officer Takeuchi

Ren Imaizumi as Sunagawa

Jun'ichirō Mukai as Military officer

Rinsaku Ogata as Goro

Ichirō Chiba as Chief of Police

Tsurue Ichimanji as Haru

Tateo Kawasaki as Tsunesan

Kanta Kisaragi as Suteyan

Tsuruko Mano as Osumi

Jirô Suzukawa as Yoshizo

Yasuhiro Shigenobu as Sabu

Keiji Sakakida as Tahei

Ichirō Nakatani as Senkichi

Kiyoshi Takagi as Dr. Minakami (uncredited)

Fuyuki Murakami as Professor Minami (uncredited)

Mitsuo Matsumoto as Professor Isokawa (uncredited)

Takuzō Kumagai as Policeman Tashiro (uncredited)

Yasuhisa Tsutsumi as Imamura, F-86F pilot (uncredited)

Yutaka Oka as Kitahara, F-86F pilot (uncredited)

Shigemi Sunagawa as F-86F pilot (uncredited)

Katsumi Tezuka as Rodan / Meganulon / Hotel Manager

Haruo Nakajima as Rodan / Meganulon

Shōichi Hirose as Meganulon / Fighter pilot

Saburô Kadowaki as Sunagawa's colleague (uncredited)

Yasuko Nakada as Female Honeymooner (uncredited)

Junnosuke Suda as Coroner (uncredited)

Toshiko Nakano as Kiyo's neighbor (uncredited)

Saburô Iketani as News Reader (uncredited)

Saeko Kuroiwa as Nurse (uncredited)

Bontarō Taira as Laborer (uncredited)

Keiichirō Katsumoto as Coal mine employee (uncredited)

Kamayuki Tsubono as Policeman at crime laboratory (uncredited)

Mike Daneen as Okinawan correspondent (uncredited)

Masaaki Tachibana as Policeman (uncredited)

Tadashi Okabe as Journalist (uncredited)

Kôji Uno as Reporter (uncredited)

Akira Yamada as Radio operator on jeep (uncredited)

Ren Yamamoto as Soldier in jeep (uncredited)

Tokio Ôkawa as Meganulon (uncredited)

Seiji Onaka as Nakagawa, male honeymooner