An ice-making device for a refrigerator, which is designed to separate ice through a simple process is provided. The ice-making device for a refrigerator includes an ice tray defining an ice-making space, an ice core member that is partly received in the ice-making space to make ice at an end thereof, a driving unit moving and rotating at least one of the ice tray and the ice core member, and a power transmission unit for transferring power from the driving unit to the ice core member. The ice on the ice core member starts being separated in a state where the ice is spaced apart from an outer surface of the ice tray.