A drilling tool for maintaining a borehole and for cutting rock material, comprising a hollow elongated body in the form of a pipe, the body having a longitudinal axis and being provided with a plurality of cutting blades arranged around the body in such a way that they protrude from the external surface of the body , the drilling tool having an upper end, wherein the cutting blades are grouped into sets arranged on the periphery of the body, - wherein in each set , the cutting blades are shaped as bands , the ends of which are connected to the body , and the central parts of the cutting blades between the ends protrude from the body , and in each set the cutting blades are placed one upward of the other and are angularly offset relative to each other, - wherein in each set , each cutting blade in the set is spaced from the axis of the body of the drilling tool by a dimension larger than the dimension of the distance from the axis of the body of the cutting blade located directly downward of it, - wherein the body is provided with slots connecting the interior of the body to its external surface and arranged radially under the cutting blades , and not connected to the cutting blades , and, in use, drilling fluid flows through the interior of the body , - wherein in each set , the bands of the cutting blades form, in their central part, a lateral channel extending in parallel to the longitudinal axis substantially on the external surface of the body and under the bands of the cutting blades , and, in use, the drilling fluid along with cut rock material flows through the lateral channel , - and wherein, in use, a zone of lower pressure under the cutting blades in lateral channels is obtained, allowing suction of the cut rock material, and then its fragmentation through transverse flow of the drilling fluid. - wherein in each set , the cutting blades are shaped as bands , the ends of which are connected to the body , and the central parts of the cutting blades between the ends protrude from the body , and in each set the cutting blades are placed one upward of the other and are angularly offset relative to each other, - wherein in each set , each cutting blade in the set is spaced from the axis of the body of the drilling tool by a dimension larger than the dimension of the distance from the axis of the body of the cutting blade located directly downward of it, - wherein the body is provided with slots connecting the interior of the body to its external surface and arranged radially under the cutting blades , and not connected to the cutting blades , and, in use, drilling fluid flows through the interior of the body , - wherein in each set , the bands of the cutting blades form, in their central part, a lateral channel extending in parallel to the longitudinal axis substantially on the external surface of the body and under the bands of the cutting blades , and, in use, the drilling fluid along with cut rock material flows through the lateral channel , - and wherein, in use, a zone of lower pressure under the cutting blades in lateral channels is obtained, allowing suction of the cut rock material, and then its fragmentation through transverse flow of the drilling fluid. <EOS>