If you are looking for outdoor equipment, like sleeping bags, cooker (and fuel for it), backpacks, then have a look at Partioaitta, which is located downtown.
What to buy: Outdoor equipment.
There is almost anything you would want located on Rotuaari.
What to buy: Sporting goods and Finnish glass products. A good store for sporting goods is Stockmann located one block east of Rotuaari.
Good place for shopping, especially for food shopping is the market hall, you can find fresh what ever you look for and also good snacks to eat in between meals.