If your electric oven recently started performing poorly, or even stopped working altogether, fixing it yourself might be simpler than you think. An oven, after all, is basically just an insulated box with a heating element and a thermostat. This means there are only a few things that could possibly be wrong with it, and the solution in most cases is identifying and replacing whichever component is failing.
If your oven won't heat at all, the most likely problem is a blown fuse or a burnt out element. Assuming you're not attempting to repair an antique, your oven will have a clock. If it has also stopped working, it's safe to assume the oven is not getting electricity. Check your circuit breaker box and reset the breaker if necessary and see if this fixes the problem. If not, cut power to the oven at the breaker box before going any further. Note that your oven runs on 220 volts. There should be a double switch on the circuit breaker board controlling power to it. If not, there will be two single switches that need to be tripped to cut power to the oven.
Even if you didn't find a blown circuit breaker, the problem could still be a blown fuse. Some older ovens have their own set of fuses located under the range top, in the back of the oven space, or behind the oven. Inspect the fuses and replace any that have blown with one of the same amperage. Your oven might also have a circuit breaker with a reset button on the control console or on top of the oven that needs to be reset.
If you are still confounded, pull the oven away from the wall. If it is a range/oven combo, make sure it is plugged securely into the wall. If it is a stand-alone oven, inspect the wiring in the junction box to make sure everything is tightly connected and the wiring doesn't show any signs of damage.
If your oven is getting power but is not heating up, check the oven and broiler elements. Start with the oven element, which generally gets more use and will fail first. With the oven on, check to make sure the entire element is glowing uniformly. Repeat the process looking at the broiler element. If either glows unevenly, or has areas of damage where the element appears melted, then it needs to be replaced. After letting the oven cool, cut power to the oven at the breaker board (or by unplugging it for ovens with range tops). Remove any brackets holding the damaged element in place, setting them aside to be used with the new element. Lastly unscrew the bracket at the rear of the oven, which will expose the wiring. If the wires from the oven to the element are the same color, or if you have any doubts about your ability to remember which wire goes where when you install the new element, use masking tape and a pen to label the oven's wires. Disconnect the wiring, remove the damaged element, and take it to an appliance store to get a replacement.
Install the new element exactly as the old one had been, replacing any brackets you had removed. Once it's in, restore power to the oven and test the new element.
Thermostat replacement is best left to a professional, but before you spend that money, you can verify that the thermostat is the problem yourself. Put an oven thermometer in the oven, then set the heat to 300, 400, and 500 degrees. If the thermostat is consistently off by 50 degrees or more with each increase in temperature, it should be replaced.