Before each use of your chain saw, checking the oil level in the chain oil reservoir will determine whether or not plenty of oil is available for use. If the oil level is low, then add oil before proceeding. Your user's operation manual for the chain saw includes the best kind of oil for that model. 

To check that oil is being pumped on the chain and bar, start the chain saw's engine, and allow it to run for a few minutes. Point the tip of the chain saw blade toward a piece of wood, and allow the chain to rotate around the guide bar. Check the nearby wood to ensure that the chain throws small amounts of oil during operation and before cutting.

Failure to maintain a supply of oil to the chain and bar will result in damage to the chain and bar, it may also damage the chainsaw too.