A drill comprising: a drill main body configured to be rotated around a shaft center; a plurality of discharge grooves provided in a helical shape in an outer peripheral surface, from a leading end portion toward a base end portion of the drill main body; a cutting edge formed on a ridge section between an inner face of the discharge groove that is oriented toward a rotation direction side of the drill main body, and a flank of the drill main body at the leading end portion; a thinning edge provided at the leading end portion of the drill main body and extending from an inner end of the cutting edge toward a chisel portion that is a leading end section of the drill main body; and a gash portion, a ridge with respect to the flank extending in a circular arc shape from an inner end of the thinning edge, connecting to the discharge groove further to an inner peripheral side than the outer peripheral surface of the drill main body, wherein the gash portion includes a circular arc groove that have a circular arc shaped in a cross section, and that is provided in a section that connects a gash face of the gash portion and a thinning face which is a rake face and which connects the thinning edge and the discharge groove, the drill is a double-edged drill that is provided with two sets of the cutting edges, characterised in that when the drill main body is seen from the leading end, a gash furrow that indicates a distance, in a first direction, between a tangential line of one of the gash portions and a tangential line of an other of the gash portions, which follow a second direction orthogonal to the first direction along with a tangential line at the inner end of the thinning edge, is at least 0.02D and no more than 0.04D, where D is an outer diameter of the drill. a drill main body configured to be rotated around a shaft center; a plurality of discharge grooves provided in a helical shape in an outer peripheral surface, from a leading end portion toward a base end portion of the drill main body; a cutting edge formed on a ridge section between an inner face of the discharge groove that is oriented toward a rotation direction side of the drill main body, and a flank of the drill main body at the leading end portion; a thinning edge provided at the leading end portion of the drill main body and extending from an inner end of the cutting edge toward a chisel portion that is a leading end section of the drill main body; and a gash portion, a ridge with respect to the flank extending in a circular arc shape from an inner end of the thinning edge, connecting to the discharge groove further to an inner peripheral side than the outer peripheral surface of the drill main body, wherein the gash portion includes a circular arc groove that have a circular arc shaped in a cross section, and that is provided in a section that connects a gash face of the gash portion and a thinning face which is a rake face and which connects the thinning edge and the discharge groove, the drill is a double-edged drill that is provided with two sets of the cutting edges, characterised in that when the drill main body is seen from the leading end, a gash furrow that indicates a distance, in a first direction, between a tangential line of one of the gash portions and a tangential line of an other of the gash portions, which follow a second direction orthogonal to the first direction along with a tangential line at the inner end of the thinning edge, is at least 0.02D and no more than 0.04D, where D is an outer diameter of the drill.