The baby was named Francois Henri Louis Marie Guillaume.
The royal family immediately pleased interested fans and subjects with information about the name and weight of the child, and in two days already showed beautiful photos of the boy.
In the photos, the princess holds her child in her arms and kisses her gently.
Prince Guillaume sits next to them.
There are also portrait photos of the baby in the gallery published on the palace page, to see them - scroll to the right.
View this post on Instagram
A post shared by Cour grand-ducale Luxembourg (@courgrandducale)
"The Crown Prince and Princess are delighted to share with you the first photos of Prince François. They are deeply grateful for the kind messages they have received on the occasion of the birth of their second child. You can continue to send them messages at Monarchie.lu," reads the caption.
They will never become monarchs: junior heirs to royal dynasties
Pregnant for the fourth time: Blake Lively showed off her round belly in a mini dress
Duke Henri and Duchess Maria Theresa celebrated the National Day of Luxembourg