A drilling tool comprising at least one machined groove and at least one web which extend from a tip of the tool to the shank of the tool. A main cutting edge and an inner cooling channel are formed on each web. Said cooling channel extends from the tip to an opposite drill end and has a continuously extending cross-sectional contour enclosing an imaginary circle with a center point. The cross-sectional contour preferably comprises two maximum curvature values whose distance to the drill axis is greater in the direction of a line between the center point and the drill axis or equal to the distance of the center point to the drill axis. Preferably, minimum wall thicknesses exist between the inner cooling channel and (1) the outer periphery of the drill, (2) the machined surface and (3) the non-machined surface, between a minimum and a maximum.