A rotary cutting tool rotatable about an axial line, the rotary cutting tool comprising: a first rake face; and a flank face contiguous to the first rake face, wherein a ridgeline between the first rake face and the flank face constitutes a cutting edge, in a cross section perpendicular to the axial line, the first rake face is constituted of a plurality of straight line portions, a first swarf discharging flute is formed in the rotary cutting tool, the first swarf discharging flute is provided helically around the axial line, a portion of the first swarf discharging flute is constituted of the first rake face and a first swarf discharging surface, the plurality of straight line portions include a first straight line portion and a second straight line portion, the first straight line portion being contiguous to the flank face, the second straight line portion being inclined with respect to the first straight line portion, the second straight line portion being contiguous to the first straight line portion, a first angle (θ 1) formed by the first straight line portion and the second straight line portion is more than or equal to 160°, the plurality of straight line portions include a third straight line portion and a fourth straight line portion, the third straight line portion being inclined with respect to the second straight line portion, the third straight line portion being contiguous to the second straight line portion, the fourth straight line portion being inclined with respect to the third straight line portion, the fourth straight line portion being contiguous to the third straight line portion, characterised in that a second swarf discharging flute is formed in the rotary cutting tool, the second swarf discharging flute is constituted of a second rake face and a second swarf discharging surface contiguous to the first swarf discharging surface, the first angle (θ 1) is more than a second angle (θ 2) formed by the second straight line portion and the third straight line portion, and the second angle (θ 2) is more than a third angle (θ 3) formed by the third straight line portion and the fourth straight line portion. a first rake face; and a flank face contiguous to the first rake face, wherein a ridgeline between the first rake face and the flank face constitutes a cutting edge, in a cross section perpendicular to the axial line, the first rake face is constituted of a plurality of straight line portions, a first swarf discharging flute is formed in the rotary cutting tool, the first swarf discharging flute is provided helically around the axial line, a portion of the first swarf discharging flute is constituted of the first rake face and a first swarf discharging surface, the plurality of straight line portions include a first straight line portion and a second straight line portion, the first straight line portion being contiguous to the flank face, the second straight line portion being inclined with respect to the first straight line portion, the second straight line portion being contiguous to the first straight line portion, a first angle (θ 1) formed by the first straight line portion and the second straight line portion is more than or equal to 160°, the plurality of straight line portions include a third straight line portion and a fourth straight line portion, the third straight line portion being inclined with respect to the second straight line portion, the third straight line portion being contiguous to the second straight line portion, the fourth straight line portion being inclined with respect to the third straight line portion, the fourth straight line portion being contiguous to the third straight line portion, characterised in that a second swarf discharging flute is formed in the rotary cutting tool, the second swarf discharging flute is constituted of a second rake face and a second swarf discharging surface contiguous to the first swarf discharging surface, the first angle (θ 1) is more than a second angle (θ 2) formed by the second straight line portion and the third straight line portion, and the second angle (θ 2) is more than a third angle (θ 3) formed by the third straight line portion and the fourth straight line portion.