A tool unit for a cutting device includes a rotary blade, a blade case for covering at least a part of the blade case, and a drive device mounted to the blade case for rotatably driving the rotary blade. A handle is attached to the drive device. The blade case has a front support portion. The handle has a rear support portion. When the tool unit is used for a portable cutting device, the front support portion can be vertically pivotally supported by a front portion of the base, and the rear support portion can be supported by a guide member such that a position of the rear support portion can be changed relative to the guide member for enabling adjustment of a cutting depth of the rotary blade into the workpiece. When the tool unit is used for a table cutting device, the front support portion can be vertically pivotally supported by the table.