Usually open from 10am to 7pm, some of them are open later. Some supermarkets close at 10pm or even later. You can classify two different kinds of supermarkets:

Local market places are Rue Levis (metro Villier), Montorgueuil (metro Réaumur-Sébastopol) or Rue du Commerce (metro La Motte-Picquet Grenelle), in addition to other markets.

The main area for fashion and big department stores is Boulevard Haussman (metro Haussman or Opéra) where are les Galleries Lafayette and le Printemps. A more eccentric or kitsch area is Le Marais (metro St Paul).

Since recently you can also do a lot of shopping (for food as well as for other things) through the Internet:

The delivery is usually about 8 €.

French people are also used, as for a lot of people, to order take away meals. The best known is obviously Pizza-Hut.