Collector Thammarit Jira has donated 104 historical artifacts dating back as far as 4,300 years to the government for safekeeping as national treasures.
They were handed over at the Bangkok National Museum on Friday, where they were accepted by Prime Minister Prayut Chan-o-cha.
"These ancient objects are very precious and useful for the study of archaeological subjects and Thai history... This is a good example, and will encourage Thai people, including younger people, to love and protect our national treasures," Gen Prayut said.
The prime minister said Mr Thammarit's action should inspire other collectors to follow suit.
The donated items are between 1,800 and 4,300 years old. They include stone, glass and shell ornaments, bronze tools and clay pots. They were found at archaeological digs in Udon Thani, Sakon Nakhon, Nong Khai and Lop Buri provinces, officials said.
The Fine Arts Department would examine the artifacts and use modern scientific methods to ensure their preservation. Later, they would be stored at the Bangkok National Museum for display and study.
Mr Thammarit said his father had begun collecting archaeological treasures because he did not want foreign collectors to have them. The family had continued in his footsteps.
They were now returning these national treasures to the kingdom, in the interests of education and the national interest, he said.