A method of inputting a cutting direction for automatic programming determining the cutting direction of a path comprises the steps of displaying the locus of a path constituted by a plurality of path blocks (b1 to b15) on a display screen (105) using path data, indicating with a cursor (CSR) an appropriate start point (P2) and an end point (P15) of the path, inputting a cutting direction by the operation of a cutting direction input switch when the path start point (P2) is indicated by the cursor (CSR) when cutting is to be effected from a start point (P1) to an end point (P16) of the passage, and inputting the cutting direction by the operation of the cutting direction input switch when the path end point (P15) is indicated by the cursor (CSR) when cutting is to be effected from the path end point (P16) to the start point (P1).