Yes it is plastic, but very durable and sturdy. Have used it to puree sauces and liquify a hot starter mixture for a soup. I took the mix from the pot after boiling for ten minutes, poured a cup of hot liquid with the other contents straight into the blenders jar, and the set for hi speed and liquified. I have done this soup on three different occasions and the jar is still in pristine condition, no scratches, scuffs. or heat warp marks. It took me a while of searching online to find this blender that ended up being my right choice for what I wanted. Good luck in your purchase choice.