To simply and rapidly adapt a slotting milling tool to various requirements for uses of different kinds.

This slotting milling tool is provided with a housing 2 having a motor 1, a milling cutter 10 connected to the motor 1 through a motion transmitting means, and a carriage 5 movable in a longitudinal direction with respect to the housing 2. This carriage 5 has an opening 7 for advancing the milling cutter 10 and a flat setting face 5'. Further, a stopper plate 9 is provided which is adjustable for an interval and an angle with respect to a milling plane formed by the milling cutter 10, and the milling cutter 10 is disposed to a driving shaft 12 formed movably in a substantially vertical direction along an axial line proper to the setting face 5'.