An apparatus for cutting a piece of work has a work supporting table which is movable only in one horizontal direction, and a spindle unit including a cutting tool which is disposed below the table for cutting the work from below. The spindle unit is movable in another horizontal direction perpendicular to the direction in which the table is movable, and in a vertical direction. The apparatus requires only a small space for installation, is simple in construction, an can perform an accurate cutting job at a high speed.