The sick celebrations were also attended by top military and party officials who contributed to the provocative test, said to be the country’s sixth and largest.
Guests were treated to a banquet, art performances and a photo sessions with Kim at the People’s Theatre in North Korean capital Pyongyang.
Kim said the scientists and technicians “brought the great auspicious event of the national history, an extra-large event through the perfect success in the test of H-bomb”.
He praised the developers for “taking the lead” in attaining the “final goal of completing the state nuclear force” in line with his parallel pursuit of nuclear and economic development.
He said: “The recent test of the H-bomb is the great victory won by the Korean people at the cost of their blood while tightening their belts in the arduous period.”
Photos of the party show crackpot Kim breaking into broad smile as he chats with two prominent scientists: Ri Hong Sop, head of North Korea’s Nuclear Weapons Institute, and Hong Sung Mu, deputy director of the ruling Workers’ Party of Korea’s munitions industry department.
Ri and Hong have played vital roles in the North’s nuclear programme, appearing at close distance to Kim during field inspections and weapons tests, including the latest nuclear test.
Ri is a former director of Yongbyon Nuclear Research Centre, North Korea’s main nuclear facility north of Pyongyang, where Hong also worked as a chief engineer.
Ri and Hong’s roles have also been noted overseas, prompting the United Nations, the United States or South Korea to blacklist them.
North Korea said last week’s test was an advanced hydrogen bomb.
There was no independent confirmation but some Western experts said there was enough strong evidence to suggest the hermit state has either developed a hydrogen bomb or was getting very close.
South Korea had been bracing for another long-range missile launch in time for the 69th anniversary of North Korea’s founding on Saturday but no fresh provocations were spotted while the North held numerous events to mark the holiday.
Throughout last week, South Korean officials had warned the North could launch another intercontinental ballistic missile in defiance of UN sanctions and amid an escalating stand-off with the US.
Washington told the UN Security Council to call on a meeting to vote on a draft resolution establishing additional sanctions on North Korea for its missile and nuclear programme.