To scrape off adherents surely from the surface of a roll by setting a scraping blade opposite the surface of the roll and installing a resistance in the rear of the blade.

A scraping blade 32 is set opposite to the surface of a roll, and a resistance 33 is installed at the back of the blade 32 in the rotational direction of a roll 13. During the normal operation of a roll crusher, a scraper is always contacted with adherents M on the surface of the roll 13. Since the blade 32 parallel to the surface of the rotating roll 13 is contacted with the adherents M, most of them M is scraped off by the blade 32. The residual thin layer adherents M is brought into contact with the resistance 33 to be scraped off surely.