The episode titled "A Katy Or A Gaga" the brand new episode premieres on November 7th.
In the clip Adam is seen performing Lady Gaga's 'Marry The Night'.
Speaking about his role, Lambert said in a statement: "It was such warm welcome on my first day on set. The cast were so sweet and they have a family vibe so I instantly felt I was in a safe, creative place with them and we jumped right in. Excited to be on set again!"
Lambert appeared on the set to film in late September. 'Glee' star Lea Michele posted a picture from set showing Lambert and the cast behind microphones. Glee star Naya Rivera and other Glee personal took to their official Twitter accounts to welcome and praise Lambert.
His appearances on the Glee set follows on his critically acclaimed performance with Queen last month at the iHeartRadio Musical Festival Village in Las Vegas where the band headlined a set which included "We Will Rock You", "We Are The Champions", "A Crazy Little Thing Called Love" and "Bohemian Rhapsody" and more.
Besides appearing on the fifth season of "Glee", Lambert is currently recording his third studio album.
Click on the link to see the first promo clip featuring Lambert.
For more information on Glee: www.fox.com
For more information on Adam Lambert: www.adamofficial.com