@markus Sometimes you can achieve that by having a separate form for that role with fields disabled. Another option that requires coding is to remove access on their role to that record and create a Suitelet (that runs in permissions of a different role) they can use to update specific fields

Thanks! I was a bit afraid that answer is going to be something like this. Of course separate form could be answer in this case. I didn't think that earlier. I need to think about that. Do you know / see any big problems if you use form to "restrict" the rights?