蒙尼卡 & Sheeta,
Thanks for your quick reply!
Yesterday I went to ask for the promotor in Seiyu, she taught me to push down the oven door slightly, since the 門'教' of the new oven is very tight. Then I try again, but really 一拉一驚心, at last I can pull out the tray.
以後要向你們一班大師傅多多指教!