Overall, consumer prices rose 1.4 percent from a year ago, the Federal Statistics Office said on Thursday, the same rate as in March. The rise was mainly driven by costly oil, fuel.
However, core inflation, which strips out volatile prices such as fuel, inched down to 0.3 percent and even to 0.2 percent when also excluding government-set prices. Both rates had been at 0.5 percent in March.
The Swiss National Bank has been intervening in the currency market to keep the Swiss franc stable against the euro, which has come under massive pressure from the euro zone debt crisis.
SNB Chairman Philipp Hildebrand said last week the euro zone crisis could prompt investors to pile more money into the traditional safe haven franc, driving the currency higher and raising the risks of deflation pressures.
Hildebrand said the central bank was therefore acting decisively to prevent too sharp a rise in the franc.
The debt crisis in the euro zone has also raised doubts the SNB will increase interest rates this year. Markets have scaled back rate hike expectations, only pricing in a full increase by March 2011.