hello to all
I am looking for embedded system based on ARM that can tolerate -40 up to +60 centigrade.

how can I find it ?
thanks for your attention

Google - unless you provide a lot more information about what you need no better advice is possible.

What board capabilities?  What core?  M-something, A-something, R-something?

Processors with the Cortex-M or Cortex-R cores in that temperature range will be thick on the ground, because those cores are targeted for general embedded and safety-critical embedded, respectively.  If you were just looking for chips you should be able to get just about whatever you want, in -40 to +125, with a few more available at -40 to +85.

If you're looking for Cortex-A cores and full-up boards (like Beagleboard, Pi, or something professional) then your choices will probably be more limited, and Michael's advise about Google is to be followed.  In fact, I got curious and in less than a minute I found this: http://www.winsystems.com/product/sbc35-c398q-2-0/.

Keywords were "ARM", "Cortex A" and "industrial temperature range".