I need to build up a DMZ with a PIX506. My idea is to make a trunk between PIX and switch, assign a VLAN for the DMZ.
Mi question is, can PIX506 handle firewall-rules between the VLAN's (internal <-> dmz)?
Not sure what you are asking here. The 506E supports up to 2 vlans on an interface so you can do what you want. Each vlan interface is treated as a physically separate interface in terms of security levels/access-lists etc.
So if you have an inside and a DMZ on the same interface you can apply separate access-lists to each interface.
Does this answer your question ?