A:Answer Panasonic Team's answer is incorrect...
Here is the info directly from the manual ( https://help.panasonic.ca/PCS/OperatingInstructions/NN-CD87KS_EN_USA_OM.pdf ):
"Allow 6 inches (15 cm) of space on the top of the oven, 4 inches (10 cm) at back and 2 inches (5 cm) on both sides. If one side of the oven is placed flush to a wall, the other side or top must not be blocked. Do not remove feet.".