Is your electric oven smoking and there's no food in it? Ovens, toasters, space heaters, and other electric appliances with heating elements can smoke and smell for a variety of reasons. While you may be concerned that this is an electrical problem, usually it's just something that is on or near the element, and it's being burned, or at least superheated, by the sudden, intense heat of the element turning on. In some cases, the material will burn off, and the smoke and smell will dissipate. In other cases, you might have a fire hazard on your hands, so be sure to check it out before letting the problem burn itself out.
Electric elements in new ovens often have a factory coating, such as oil, that protects the elements during storage. The coating usually burns off when the device is turned on for the first time. There may even be a noticeable amount of smoke. New ovens can also smell from other internal parts, such as insulation or adhesives used during manufacturing. Sometimes the first use of an oven helps cure adhesives and other materials. Appliance manufacturers often recommend cleaning the oven racks (and sometimes the entire oven interior) with soap and water, then heating the oven for 30 minutes or more to burn off factory coatings.
A smelly or smoky element is also likely if an appliance has been idle for long periods of time. This is due to the settling of dust, cobwebs, and other particles onto the element, and you get the smoky smell on the first burn of the year. The same thing happens with a forced-air furnace when you first fire it up in the fall. A small amount of dust on heating elements is harmless, and the smell goes away in a few minutes, but it's a good idea to clean electric baseboard heaters and portable space heaters at the beginning of each heating season. Dust and cobwebs can inhibit heat transfer and restrict airflow, making a heater less efficient and more prone to overheating.
Food and Grease
Most electric ovens have two heating elements. One is a bake element at the bottom of the oven, and the other is a preheat/broiler element at the top of the oven. Preheat/broiler elements can get grease splatter from food, but it's much more common to have food spill onto the bake element below. Small amounts of grease and food usually burn off in a few minutes, while large spills or chunks of food can easily ignite and flame up, creating a fire hazard. If your oven is smoking from food that's created a small fire, turn off the oven and put out the flame with a handful of salt, or use an appropriate type of fire extinguisher. Let the oven cool completely, then clean the oven before using it again. If the oven is smoking—but there's no flame—you can scrape off the food from the element with a heatproof plastic spatula or similar tool. Don't use metal because it can damage the element, and, after all, it does have high-voltage electricity running through it.