Actually, the editor is called 'voxed'.

Let's say you started a server (please don't ask how to do this... if you can't run the basic game then map editing probably isn't going to be your thing) and used the 'gen' command to generate some basic terrain. You'd connect locally to that game and hit alt-F1 to save a map. Exit server. Load that map into the map editor, 'voxed' and edit it. As stated above, F1 (like many ten year old programs... those were the days) will open up a help screen. There's also a text version of that file that I highly suggest you review. The program has a fairly arcane set of commands and features but is actually pretty powerful. If you want to edit smaller objects you would use the editor called Slab6 and I assume you might be able to create objects in that and import them into 'voxed' for placement. You then might find it useful to load your new map onto your server and do some fine-tuning the normal and save again. Rinse and repeat. Viola!

Oh sry, im new to the forum. But tnx :D

Use the search darn it.
Ben released a map editor along with 0.42. It's named 'voxel' and can be found in your Ace Of Spades directory.
Use F1 to figure out how to use it.

I am thinking of making my own server, but then i need a custom map.
Does someone know an AOS map editor, or do you make the map by hand?