Shani Puja is to appease the planet Saturn. Saturn Puja is very useful & beneficial puja, since it's worship strengthens benefic Saturn & increases its positive influence and pacifies malefic effects of the planet & neutralizes its negative effect. Saturn Puja is recommended for those having malefic Saturn or wrongly placed Saturn as per horoscope.

The planets are to propitiated against their evil influences, to ward off them, the Saturn Puja is done with faith to ward off all evils of Saturn as per the horoscope.