Thailand has recorded 42 coronavirus cases since January, with 30 of those recovering and 11 still being treated in hospitals, according to the department.
Thai health officials said the dead man had worked in the retail sector, where he had come into contact with many tourists during the early stages of the outbreak.
"This was a case of local transmission, and he was at risk because he had exposure to Chinese tourists," Suwanchai said, speaking at a news conference.
The patient was first admitted to a private hospital for dengue fever on Jan. 27.
He was later diagnosed with the coronavirus and transferred on Feb.5 to the government's main treatment centre, Suwanchai said.
He died from multiple-organ failure late on Saturday.
New measures to deal with the spread of the coronavirus - earlier introduced by Thailand's National Committee on Communicable Diseases - came into effect on Sunday.
Health officials can now order those suspected of being infected to be quarantined and to undergo treatment.
Officials can also order the closure of venues and public areas to contain the virus. - Reuters