I used to have quite a lot of trouble with dust, but after cleaning the sensor AND the mirror chamber, I don't seem to see much if any. I suspect that quite a lot of so called dust is debris and dirt from the manufacturing of the camera, including oil on the mirror and shutter mechanisms.

I suspect Don is right about some lenses being worse than others. My lenses tend to be internal focussing designs, or primes with little extension.

I feel it is a bit idotic thing to ask,-I think I need to clean my D-70's ccd, can somebody plz, help me, how to do it ?? B'coz I am resideing in a small town where having a dslr is a big thing, so forget about going to service center.There is no sevice center even in nearby big city, And the so called camera repairer are actully are novice trying to sound big ,No confidance on them. PLZ HELP ME..

The method is described on

http://www.copperhillimages.com/index.php?pr=Tutorials

In UK you can get a kit from

http://www.cameraclean.co.uk/acatalog/index.php

there may be other kit suppliers but these guys are 24 hour service

I personally agree entirely with copper hill to forget blowers and vacuums etc, so don't spend money on them.

Thanks daedal for reponse