A cutting tool comprising: a cutting tool shim, a cutting insert and a holder, the cutting tool shim being disposed between the cutting insert and the holder and being fixed to the holder, the cutting insert including a flank face and a rake face continuous with the flank face, a ridgeline between the flank face and the rake face forming a cutting edge, the cutting edge including an arc-shaped portion, a coolant supply path for jetting coolant to the arc-shaped portion being provided in the cutting tool shim, the coolant being supplied from the holder, the coolant supply path including a lead-in port for leading the coolant from the holder to the coolant supply path, and a jetting port for arc-shaped portion for jetting the coolant to the arc-shaped portion, the jetting port for arc-shaped portion having a curved shape along the arc-shaped portion, a distance between the jetting port for arc-shaped portion and the arc-shaped portion being not less than 2.2 mm and not more than 8.1 mm, characterised in that: the cutting edge further includes a linear portion continuous with the arc-shaped portion, the coolant supply path further includes a first jetting port for a first linear portion for jetting the coolant to the first linear portion, and a second jetting port for a second linear portion for jetting the coolant to the second linear portion, and the jetting port for arc-shaped portion is smaller than the lead-in port in area. the cutting insert including a flank face and a rake face continuous with the flank face, a ridgeline between the flank face and the rake face forming a cutting edge, the cutting edge including an arc-shaped portion, a coolant supply path for jetting coolant to the arc-shaped portion being provided in the cutting tool shim, the coolant being supplied from the holder, the coolant supply path including a lead-in port for leading the coolant from the holder to the coolant supply path, and a jetting port for arc-shaped portion for jetting the coolant to the arc-shaped portion, a lead-in port for leading the coolant from the holder to the coolant supply path, and a jetting port for arc-shaped portion for jetting the coolant to the arc-shaped portion, the jetting port for arc-shaped portion having a curved shape along the arc-shaped portion, a distance between the jetting port for arc-shaped portion and the arc-shaped portion being not less than 2.2 mm and not more than 8.1 mm, characterised in that: the cutting edge further includes a linear portion continuous with the arc-shaped portion, the coolant supply path further includes a first jetting port for a first linear portion for jetting the coolant to the first linear portion, and a second jetting port for a second linear portion for jetting the coolant to the second linear portion, and the jetting port for arc-shaped portion is smaller than the lead-in port in area. the cutting edge further includes a linear portion continuous with the arc-shaped portion, the coolant supply path further includes a first jetting port for a first linear portion for jetting the coolant to the first linear portion, and a second jetting port for a second linear portion for jetting the coolant to the second linear portion, and the jetting port for arc-shaped portion is smaller than the lead-in port in area.