Provided is a descaling device for effectively removing scale formed on a surface of a hot-rolled steel strip (steel sheet). The descaling device, for example, may be configured to include: a device housing disposed in a feed path of a hot-rolled steel strip, a high-pressure fluid supply unit provided to supply a high-pressure fluid to the device housing, an abrasive input unit provided to introduce an abrasive to the device housing, and an abrasive slurry spraying unit provided in the device housing to spray an abrasive slurry of the high-pressure fluid and the abrasive mixed inside the device housing on the steel strip.