It is likely that the oven is faulty given the information you have provided.

Hi,
从你提供的信息oven sounds faulty or in could be a loose connection on the oven outlet or on the back of the oven. Hope this helps.

Hi,I would say a loose connection at the Oven wall switch or faulty Oven.
Get a Electrician to check the supply voltage.

Hire an Electrician to take a look, could be a loose connection in cooker outlet or oven, possible faulty cooker but like I said get someone to take a look who is competent.

The information provides would suggest their is an issue on the load side of the wall switch meaning either their is a fault on the cable leading to the oven or a fault with the oven itself. I would seek the advice of a qualified electrician before looking into the possibility of a faulty oven