The ministry advised that inflation should be within a range of 2-2.8 per cent this year.
Commerce Ministry adviser Ampawan Pichalai said the Consumer Price Index in May stood at 107.90 points, rising by 2.62 per cent year-on-year.
The increment was the highest in 14 months as prices of foods and alcohol-free beverages increased by 4.39 per cent.
Of 450 surveyed items, 233 were more expensive, 76 were cheaper and the prices of 151 products remained the same.
Price increases were mainly for to ready-to-eat foods due to the increase in the prices of their raw materials including pork, chicken eggs, fresh vegetables and aquatic animals.
Food price rises also resulted from oil and cooking gas prices edgingd up since last September and from the rising electricity fee.
In the first five months of this year inflation ran at 2.21 per cent.
As the National Council for Peace and Order caps the diesel price at Bt30 per liter, it slows down inflation by 0.46 per cent. Besides, the council's decision to freeze cooking gas prices reduce inflation increment by 0.03 per cent.
Inflation should be 2.25 per cent in the first half of this year and at 2.4 per cent in the second half.
The Ministry of Commerce is confident that it can keep inflation at 2-2.8 per cent throughout this year.