He is 112 years old.
Nonaka who lives in Ashoro in Japan's norther island of Hokkaido received the certificate from the Guinness World Book of Records and ordered a cake to celebrate.
He was born in 1905.
According to Time, Nanoko's secret to longevity is soaking in Japan's hot springs and eating sweets, especially cakes.
He reads a newspaper after breakfast every morning, and loves to watch sumo wrestling and samurai dramas on TV, soaking in hot springs and relaxing.
Nonaka has outlived his wife, two of their five children.
The previous record holder of world's oldest man was Spain's Francisco Olivera who was 113.
The world's oldest person on record is Japanese woman Nabi Tajima who is 117 who replaced replacing Violet Moss-Brown of Jamaica, who died in September at age 117.