Very good point from Crafty. Please go and make a note of what's written on the thing that keeps tripping, and tell us.
If you were getting an overload, then it shouldn't be the oven alone. Look and see if it is connected with a 13Amp plug. If it is, look and see if it has a 13Amp fuse in it, not anything else. If it doesn't have a 13Amp plug, does the flex go into quite a large plastic outlet on the wall, and is there a large Cooker switch to turn it on?
Do you have electric heaters running off the same ring, and/or a dishwasher, tumble drier, washing machine at the same time the circuit trips?