Looks like a sawfly larva. Was this taken in Denmark? 

yes it is found in Denmark
 and it sat on ash leaf. 
it is larger than the ones 
I have otherwise found and 
it looks like Cimbex connatus. 
When I touched it, it shot with
 clear fluid.

sorry if i make mistakes
​​​​​​but have difficulty
with language and your forum

No need to apologies, your English is excellent. Our problem is that we don't know much about Denmark since this website is devoted to the wildlife of Leicestershire and Rutland. Perhaps someone else might recognize this species and be able to comment. 

Thanks ?
The reason I fell over your forum was a thread with a larva similar to this one, photo by David Nicholls, so hoped someone could help?

It is a sawfly larva, probably the Birch Sawfly Cimbex femoratus.