This is an English forum, so I apologize but I'll reply in English (I used Google to translate your message so I hope I'm getting it right).
To access phpMyAdmin, open the Zend Server GUI and click on the phpMyAdmin link in the dashboard.
Like most other MySQL installations, the admin user is 'root' with no (blank) password - you can change that password later on from the Start menu.
Shahar Evron <firstname.lastname@example.org>
Product Manager, Zend Technologies