… as for the why?
With Japan still suffering from a shortage of food in the post-war era, the Ministry of Health tried to encourage people to eat bread made from wheat flour that was supplied by the United States. Ando wondered why bread was recommended instead of noodles, which were more familiar to Japanese people. The Ministry's response was that noodle companies were too small and unstable to satisfy supply needs, so Ando decided to develop the production of noodles by himself. The experience convinced him that "Peace will come to the world when the people have enough to eat."
On August 25, 1958, at the age of 48, and after months of trial and error experimentation, Ando finally perfected his flash-frying method and invented the precooked instant noodle. Called Chikin Ramen (チキンラーメン?), after the original chicken flavour, it was originally considered a luxury item with a price of ¥35, around six times that of traditional udon and soba noodles at the time. Ando began the sales of his most famous product, Cup Noodles on September 18, 1971 with the masterstroke of providing a waterproof polystyrene container. As prices dropped, ramen soon became a booming business. An estimated 70 billion servings were sold in 2004. As of 2007, Chikin Ramen is still sold in Japan and now retails for around ¥60, or approximately one third the price of the cheapest bowl of noodles in a Japanese restaurant.