Momofuku Ando, who died on January 5 at age 96, was symbolically blasted off into space at a ceremony in a baseball stadium in the western city of Osaka.
Ando triggered a revolution in 1958 when he created a dried noodle cake that could turn into a meal by adding hot water. His company, Nissin Food Products, now boasts annual sales of more than 300 billion yen ($2.7 billion).
"He was the creator of a culinary culture that post-war Japan can be proud of," former prime minister Yasuhiro Nakasone said in a eulogy.
Some 6 500 people attended the funeral at the Kyocera Dome, which featured projections of images from space along with chanting and synthesizer music, the company said.
A total of 34 monks officiated the ceremony, which also included a surprise visit by former prime minister Junichiro Koizumi, who was a personal friend.
Japanese astronaut Soichi Noguchi, who brought noodles into space for the first time in 2005 on the US shuttle Discovery, offered a video message from the United States.
He recalled how he and Ando jointly developed a special vacuum pack of the usually dangling delicacy in the belief that it could become the food of the space travel.
Born in Taiwan under Japanese occupation, Ando said he was inspired to develop his first instant chicken ramen after watching people in war-ravaged Osaka waiting to buy steaming noodles at a black-market stall.
His culinary contributions led him to be made an honorary citizen of Los Angeles, and he was decorated by the governments of Brazil and Thailand.
"Peace prevails when food suffices," he wrote in his autobiography.