How to Create Surface Extrude in CATIA

Catia Surface
Mechanical Design > Wireframe & Surface Design....
Go to Sketch task environment select the plane create the Sketch with any Sketch tools..
Exit Tool and then Exit the Sketch task environment...

After exiting the Sketch task environment it directly take you to Wireframe & Surface Design window.
Here with the help of Extrude tool we create surface model with the help of specified dimensions..

Refer the images....