The sequences of Ultraman battling monsters were so expensive to film, that the producers needed a way to limit the scenes to only a few minutes for each episode. The solution was to give the character the weakness that he can not survive in his true self for more than roughly three minutes before he runs out of energy. This is marked with his warning chest light, called the Colortimer, which begins to blink with increasing speed as his energy runs out.
As is the case with his previous series, Ultra Q (1965), series creator Eiji Tsuburaya uses and redecorates famous Toho monsters for the show. Baragon (from Frankenstein vs. Baragon (1965)), who was also used in aforementioned series (as the monster Pagos), was used as monsters Neronga in Episode 3 ("Sally Forth, Science Patrol!") and Gabora in Episode 9 ("Operation Lightining Speed"). And the King of the Monsters himself, Godzilla (who was also used as the monster Gomess in the first episode of Q), was used as the frillnecked dinosaur monster Jirass in Episode 10 ("The Mysterious Dinosaur Base"). Using the body of the "Mosu-Goji" suit (from Mothra vs. Godzilla (1964)) and the head of the "Daisensô-Goji" suit (from Invasion of Astro-Monster (1965), Godzilla/Jirass was fitted with a frill collar around his neck, as well as a minor paint job. This was because the script called for a reptilian monster, so Eiji said, "Okay, then, let's use a Godzilla suit!"
The character 'Ultraman' was ranked #23 in TV Guide's list of the "25 Greatest Sci-Fi Legends" (1 August 2004 issue).
When directing Episode 36, "Gift from the Sky", Akio Jissôji played a humorous prank on star Susumu Kurobe by making him mistake a spoon for the Beta Capsule when transforming into Ultraman. This became a popular in-joke to many fans of the show (even American fans like cartoonist Jeff Nicholson, who made an Ultraman parody called "Ultra Klutz", in which the title superhero transforms using a spoon).
The series was unusual for a children's show as members of the staff would also be apart of the Japanese New Wave film movement. Writer Mamoru Sasaki was a frequent collaborator with the controversial director Nagisa Ôshima. Akio Jissôji would alternate in directing episodes of the Ultra series and auteur driven erotic dramas. Cast members like Hiroko Sakurai and Yoshio Tsuchiya would appear in underground films for the Art Theater Guild.