De Wikitravel :
Switzerland is not part of the European Union and the currency is the Swiss franc (or Franken or franco, depending in which language area you are), divided into 100 centimes, Rappen or centesimi. However, many places - such as supermarkets, restaurants, sightseeings' box offices, hotels and the railways or ticket machines - accept Euro and will give you change in Swiss Francs or in Euro if they have it in cash. A check or a price-label contain prices both in francs and in Euro. Usually in such cases the exchange-rate comply with official exchange-rate, but if it differs you will be notified in advance. Changing some money to Swiss Francs (CHF) is essential. Money can be exchanged at all train stations and most banks throughout the country.
Switzerland is more cash-oriented than most other European countries. It is not unusual to see bills being paid by cash, even Fr 200 and Fr 1000 notes. Some establishments (but fewer than before) do not accept credit cards so check first. When doing credit card payments, carefully review the information printed on the receipt (details on this can be found in the "Stay Safe" section below). All ATMs accept foreign cards, getting cash should not be a problem.
Como eles mencionam, há caixas eletrônicos em todos os lugares, que é o que eu fiz quando fui - eu simplesmente peguei dinheiro na chegada. Eu faço isso em todas as minhas viagens - é conveniente, e só 'falhou' em Buenos Aires onde um dos caixas eletrônicos do aeroporto estava em baixo, e no Uzbequistão (Khiva) onde apenas um banco na cidade podia deixar você tirar dinheiro do meu tipo de cartão, e não havia caixas eletrônicos.