Originally posted by Dani I don't know. I was told in a workshop by the teacher that it needed professionally cleaned. There are many, many spots.
If the spots are dust, then you could blow them off with a Rocket Blower, taking care not to bump against the mirror or the sensor when doing so.
If, however, you're dealing with something sticky like pollen or if you sneezed into your camera
then your best course of action is to go to a good, reputable camera shop and ask if they offer a professional sensor cleaning service.
You can clean the sensor yourself, with the correct equipment, but I would suggest having it done professionally.