Non-stick pan I think may be surely made of metal. Its always
advised not to use metal pans, dishes, spoons etc inside the
microwave oven. Metals are mainly avoided due to the effect
of the microwaves on the metals.
These ovens uses the microwave radiations generated from a
magnetron. The microwave radiations are reflected off by the
metal surfaces. So if you use metal pans inside the oven, they
act as a microwave antenna that reflects back the radiations to
the magnetron and can cause damage to your oven. Another problem
with the metals inside the oven are due to arcing effect
The atoms in the metal are ionized and the air gap near them lead
to a lightning like discharge of energy causing sparks. This can
easily cause a fire inside the oven since the food materials may be
easily ignitable under that temperature.
Alternatively you could check the manuals of your oven to confirm
the type of dishes that can be used to cook inside. If no
user manuals are available check manufacturer website.
Considering the safety, its a "No" to use metal pans inside the oven.