Batman first appeared in Detective Comics #27 (May 1939), created by Bob Kane and Bill Finger.
"In early 1939, the success of Superman in Action Comics prompted editors at National Comics Publications (the future DC Comics) to request more superheroes for its titles. In response, Bob Kane created "the Bat-Man". Collaborator Bill Finger recalled that "Kane had an idea for a character called 'Batman,' and he'd like me to see the drawings. I went over to Kane's, and he had drawn a character who looked very much like Superman with kind of ... reddish tights, I believe, with boots ... no gloves, no gauntlets ... with a small domino mask, swinging on a rope. He had two stiff wings that were sticking out, looking like bat wings. And under it was a big sign ... BATMAN".
The bat-wing-like cape was suggested by Bob Kane, inspired by Leonardo Da Vinci's sketch of an ornithopter flying device as a child.
Finger suggested giving the character a cowl instead of a simple domino mask, a cape instead of wings, and gloves; he also recommended removing the red sections from the original costume. Finger said he devised the name Bruce Wayne for the character's secret identity: "Bruce Wayne's first name came from Robert Bruce, the Scottish patriot. Wayne, being a playboy, was a man of gentry. I searched for a name that would suggest colonialism. I tried Adams, Hancock ... then I thought of Mad Anthony Wayne." He later said his suggestions were influenced by Lee Falk's popular The Phantom, a syndicated newspaper comic-strip character with which Kane was also familiar.
Kane and Finger drew upon contemporary 1930s popular culture for inspiration regarding much of the Bat-Man's look, personality, methods, and weaponry. Details find predecessors in pulp fiction, comic strips, newspaper headlines, and autobiographical details referring to Kane himself. As an aristocratic hero with a double identity, the Bat-Man had predecessors in the Scarlet Pimpernel (created by Baroness Emmuska Orczy, 1903) and Zorro (created by Johnston McCulley, 1919). Like them, he performed his heroic deeds in secret, averted suspicion by playing the fool in public, and marked his work with a signature symbol. Kane noted the influence of the films The Mark of Zorro (1920) and The Bat Whispers (1930) in the creation of the character's iconography. Finger, drawing inspiration from pulp heroes like Doc Savage, The Shadow, Dick Tracy, and Sherlock Holmes, made the character a master sleuth."
The above were paragraphs extracted from wikipedia detailing the origins of Batman's creation. It couldn't have been more interesting to list out the details on how the character was conceptualised and brought to life.
As a fan ourselves, we thought why we could love the character so much was because (unlike some of the superheroes with special powers), Batman was just a mere human like many of us (with loads of money). It would be easier for the readers to relate to in real life. One may just imagined - If only if I have that kinda wealth, I could be Batman too!
And amidst those imagination, we have the "Bat Technologies". Unthinkable at that time, but as technology advances, some of the weaponry concepts are actually doable in the world today.
Bat Plane/ Batwing
The first appearance of Batman's plane was in Detective Comics #31. Some say that the present day F-117 Nighthawk and other models of stealth fighter were modeled after the once fictional concepts of the Bat Planes.
Batmobile
The initial Batmobile first made debut in Detective Comics #27, in a non futuristic fashion, the red-coloured Sedan was only referred to as Batman's car.
And it was interesting to know, at a later time, that it was actually the young Robin (Dick Grayson) who had named Batman's car the Batmobile.
Batboat/ Bat Sub
The supreme gadget was known as - an aqua-dynamic hydrofoil/submersible watercraft. The night crusader's marine vehicle first came to light in Detective Comics #110. One would be interested to know that, the wealthy millionaire did not build the first boat for his crime fighting career. In fact, it was Scotland Yard who had given the boat to him.
Batcycle/ Batblade/ Batpod
Last but not the least, Batman's very own motorcycle. Unlike the rest of his vehicles, the Batcycle first appeared on TV during his 1966 popular series.
The Batcycle featured was a modified 1965 Harley Davidson with a side-car. Later on, in the comic book universe, the bugger was replaced by a 786 cc liquid-cooled V-4 engine, containing a computer-controlled carburetor and bulletproof wind-guard.