Month-on-month, consumer prices dropped 0.1% in May, while economists were expecting it to stay flat.
Prices of food and non-alcoholic beverages slipped 1.1% year-on-year, while alcoholic beverages and tobacco prices rose 2.2%. Clothing and footwear cost increased 1.3%. Increase in housing and energy was 3.2% and transportation gained 4.1%.
Separately, the State Secretariat for Economic Affairs said the risk of inflation is expected to remain low. SECO forecast consumer price inflation to reach 1.1% in 2010, before slowing to 0.8% in 2011.