Using a spoon or metal in a microwave, is it safe?
Using metal tray In Combination Microwave Oven

Question

Accepted Answer

When using the oven you are using Microwaves in combination with the Oven. Effectively stirring microwaves in to the cavity when using the oven function.
As you are using the oven function in combination you are using a lower level of microwaves, therefore you can add the metal shelf provided.
You should refer to your operating manual for full instructions of use.
Liquids, such as water, coffee, or tea could be overheated. They can be heated beyond boiling point without appearing to boil. For example, visible bubbling or boiling when the container is rmoved from the microwave oven is not always present due to the surface tension of the water. THIS COULD RESULT IN VERY HOT LIQUIDS SUDDENLY BOILING OVER WHEN THE CONTAINER IS DISTURBED OR A UTENSIL IS INSERTED INTO THE LIQUID. When heating liquids, always place a glass rod/spoon in the container.
This will prevent delayed boiling.CAUTION Metal e.g. a spoon in a glass must be kept at least 1 inch (25mm) from the oven walls and the inside of the door. Sparks could irreparably damage the glass on the inside of the door

Manuals can be downloaded

Using a Spoon or Metal in a Microwave / Using Metal Tray In Combination Microwave Oven