Abstract: A spiral tap including: a screw portion provided with a male screw; a primary flute in a helical shape formed to intersect with a screw thread of the male screw; and a secondary flute formed in a tip portion in the primary flute at a helix angle smaller than a helix angle of the primary flute, the secondary flute having a positive or negative helix angle of 0 to 3 degrees, the spiral tap further including a cutting edge being formed on a ridgeline between a side wall surface toward a tap rotation direction out of a pair of side wall surfaces of the secondary flute and an outer circumferential surface of the screw portion and having a rake angle of ?10 to 0 degrees, and the secondary flute having a flute bottom slope of 5 to 15 degrees.