Sparks inside a running microwave are a genuine fire hazard. Stop the cycle right away and figure out what's causing it before running it again.
Remove Any Metal
Aluminum foil, metallic trim on dishware, or a stray twist tie will all cause instant arcing.
Fix: Stick to cookware that's explicitly microwave-safe with no metallic decoration whatsoever.
Check the Waveguide Cover
The small mica panel mounted on the cavity wall chars and sparks once grease splatter builds up on it.
Fix: Clean it off; if it's already charred or flaking apart, replace the cover.
Inspect the Cavity Paint
Chipped paint on the interior wall exposes bare metal underneath, which arcs.
Fix: A technician can advise on a microwave-safe repaint or whether replacement makes more sense.
Not sure what's wrong? Book online — every visit includes a free diagnosis.