Can you help me to find the font used fot the word "Campbell's"
Thank's !

Not a font but hand engraved and first appeared around 1900. NYT article here suggests;
"The Campbell script for instance is very similar to Joseph Campbell’s own signature, which may have been used as a basis for the label script.”
The script “was designed to appeal to the housewife of the time,” Thorn said. “It was intended to look like cursive handwriting of the day that one would find on handwritten recipes, equating to ‘Homemade.’ ”
http://6thfloor.blogs.nytimes.com/2011/05/09/who-made-that-campbells-soup-label/
Wahol's 'art' was just based on that brand.
http://en.wikipedia.org/wiki/Campbell's_Soup_Cans

Thank's for the information !
And, Is there a font that looks like this?

Many here:
http://www.dafont.com/theme.php?cat=601&page=3&text=Campbell%27s
Sterling could be a reasonable starting point if you used the 'l' from the alts:
http://myfonts.us/td-ul0nnp