Ampawan Pichalai, adviser to the ministry, said the consumer price index stood at 107.79 at the end of June, down 0.10% on the May index.
She said the small drop resulted from the NCPO freezing cooking gas and diesel prices and asking businesses to maintain the prices of their products for six months.
In June inflation ran at 2.35% year-on-year and in the first half of this year it stood at 2.23%, a rate considered as stimulating economic growth.
The Ministry of Commerce expects inflation of 2.50% in the third quarter and 2.56% in the fourth quarter of this year, and to average out at 2.4% throughout this year, moving between 2.00-2.80%.
Its survey of the retail prices of 450 products in June found 175 with higher prices. Prices were unchanged for 191 product items and 84 items were cheaper.