Abstract: A portable planing machine is shown that is adapted to straddle the work piece and is freely movable on a work bench. The machine comprises a pair of runners that are joined by a pair of rails or ways. An adjustable carriage is supported on the rails, and a router is fastened to the carriage. A datum or guide bar is carried by the rails to engage the side of the work piece and guide the movement of the planing machine along the length thereof. After each pass of the planing machine, the carriage is reset to reposition the cutter of the router for the next pass or travel of the machine. Special care is taken in leveling and clamping the work piece so the least amount of material need be removed to accomplish the desired result.