If these simple things are not the culprit then As mentioned earlier we can usually trace it down to just three things: Our first step would be to check the pilot light. If it is not lit it cannot ignite the burner. However, most newer gas stoves do not have a pilot light anymore. This would only be the case in older models. You can check the pilot light by looking through the burner and in the opening you should see the thermocouple. It will usually be made of copper and will be shaped like a long cylinder.
If you dont have an old school oven, you will next want to check the spark from the pilot assembly. Although not as old as the pilot light, this technology is still a bit outdated. You will know if you have this type of set up if you normally hear a clicking sound when you try to light your gas oven.
Modern gas ovens will have a glow coil igniter and can be found at the back of the burners. The process should be as follows: you turn the oven on, the igniter will turn bright and begin to glow, this will then cause the gas valve to open up which in turn will light the burner.
If the gas valve does not open up you know you have a bad igniter. Many times when the igniter is going bad it will either not glow at all or not glow very bright. This is a for sure sign that you should replace it. The good news is that this is an easy fix is one of the most common problems we see with gas ovens. Since the problem occurs a lot most Home Depots and Lowes hardware stores will have the item in stock. Be careful when removing the igniter element not to damage other parts in the process. Also be sure to turn the gas and power off before you do any work on the unit.