It's a supermarket., but it stocks up probably the more cheaper basic items to buy from anywhere else in Paris. Buy your bottled drinks here, as elsewhere it costs 2 EUR for a 125ml of Mirinda Orange! Geesh!.. You can find one near Boulevard Haussmann if you're out and about shopping...
There are lots in Paris - it is their supermarket - where they get their cheeses, milk, wines, meats... food in short...
and also a separate floor for their clothing line. Very affordable..
40Euro for a blouse
What to buy: Food - wine, cheese, bottled water... souvenirs, chocolates..
Clothes - deodorant, shampoo, laundry soap...
What to pay: cash, cc
Say you arrive in Paris and you discover you forgot your toothbrush or you need to pack that minibar with some late-night snacks.
Where should you go for such stuff? Head over to your local branch of Monoprix aka the lifesaver.
Monoprix is a mini department store, cosmetics, and grocery store all bundled up into one large store.
What to buy: Toiletries, clothing, and especially groceries
Stock up on bottled water for your daily trips and your hotel room (or you could actually save and fill up on the tap water-really it's potable). There are all kinds of pastries, fresh fruit, bread, cookies, chocolates, wine, cheese, etc...to make snacks for late at night or to take with you on the road.
Get your lotions and potions here too if you forgot to bring some from home or you hate the kinds the hotel provides.
If you arrive and need some extra clothes or accessories Monoprix has some good selections.
What to pay: Prices are average on the whole.
If you forgot something in your luggage and you don't want to pay too much for something you have at home, this "city market" (it means supermarket with a reasonable size so that you find what you want quickly) is very useful. You can find almost anything with a very reasonable price and a good rate quality/price. You also can find anything you need for children and babies. No medical stuff except the basic ones.
What to buy: Clothe, food, toiletries, cosmetics, films, bags, suitcase, hats, sunglasses, books, guides, accessories, bread and patisseries, sandwiches...
What to pay: very affordable prices
If you want to bring back food and wine gifts to friends and family, and are on a budget, instead of the higher-priced gourmet shops, try the supermarkets. They carry wines and liqueurs, pates, mustards, confections, spices and more for half the price. Not only do you save money, you'll feel a little more like a native when you browse the aisles with the locals.
What to buy: For the gourmands in your life, try getting them Fluer de Sel (special salt from Brittany) or Crýme de Marrons (chestnut cream - great for crepes).
Monoprix is another French chain department store with a little less glitz and glamour than its rival Galeries Lafayette.
What to buy: Everything is available, but I bought souvenirs and associated whatnots just like a typical tourist who didn't know any better.
What to pay: Everything was reasonably priced. It was even more so on 4 July 1986 for Americans who could show their passport (a 10% discount). See, that summer was the one after Reagan ordered Qadafi bombed and American tourists in Paris were about as scarce as Democrats in Hanover County, Virginia.