A grinder, which serves to grind coffee beans, encompassing: - a first grinding disk, which has a number of teeth (61, 67), which are spaced apart from one another and which are separated from one another by grinding grooves (60, 66) and which in each case encompass a grinding edge (63, 65) and a first grinding surface (64, 69), which adjoins the grinding edge (63, 65), - a second grinding disk, which has a number of teeth (91, 97), which are spaced apart from one another and which are separated from one another by grinding grooves (90, 96) and which in each case encompass a grinding edge (93, 95) and a second grinding surface (94, 99), which adjoins the grinding edge (93, 95), - wherein the first grinding disk and the second grinding disk are arranged coaxially along a common axis of rotation by forming a grinding slit, which extends between the first grinding disk and the second grinding disk, and in each case extend substantially vertically to the common axis of rotation, - wherein the first grinding disk and the second grinding disk are configured to be rotated relative to one another about the common axis of rotation, so that, in response to a rotation of the first grinding disk relative to the second grinding disk, each of the first grinding surfaces of the first grinding disk is in each case moved in a grinding direction relative to the second grinding disk, so as to transport the coffee beans, which are to be ground, from an entrance slit of the grinder in the grinding grooves (60, 66, 90, 96) through the grinding slit to an exit slit, and to comminute them by means of the first grinding surfaces (64, 69) of the first grinding disk, wherein each first grinding surface (64, 69) of the first grinding disk is arranged such that it defines one of the grinding grooves (60, 66) of the first grinding disk at a rear side of the respective grinding groove (60, 66) relative to the grinding direction, - wherein each first grinding surface (64, 69) of the first grinding disk encompasses an angle of inclination φ at an arbitrary point at the respective first grinding surface (64, 69), relative to a tool reference plane (E-I), measured at an assumed working plane (E-II) in the grinding direction of the respective first grinding surface (64, 69), - wherein the tool reference plane (E-I) is a plane in the arbitrary point, which is embodied parallel to the grinding direction and vertically to the axis of rotation, and wherein - the assumed working plane (E-II) is a plane, which is oriented parallel to the axis of rotation and parallel to the grinding direction, through the arbitrary point, and characterized in that the angle of inclination φ of at least one of the first grinding surfaces of the first grinding disk fulfills the following condition: 90° < φ < 180° - a first grinding disk, which has a number of teeth (61, 67), which are spaced apart from one another and which are separated from one another by grinding grooves (60, 66) and which in each case encompass a grinding edge (63, 65) and a first grinding surface (64, 69), which adjoins the grinding edge (63, 65), - a second grinding disk, which has a number of teeth (91, 97), which are spaced apart from one another and which are separated from one another by grinding grooves (90, 96) and which in each case encompass a grinding edge (93, 95) and a second grinding surface (94, 99), which adjoins the grinding edge (93, 95), - wherein the first grinding disk and the second grinding disk are arranged coaxially along a common axis of rotation by forming a grinding slit, which extends between the first grinding disk and the second grinding disk, and in each case extend substantially vertically to the common axis of rotation, - wherein the first grinding disk and the second grinding disk are configured to be rotated relative to one another about the common axis of rotation, so that, in response to a rotation of the first grinding disk relative to the second grinding disk, each of the first grinding surfaces of the first grinding disk is in each case moved in a grinding direction relative to the second grinding disk, so as to transport the coffee beans, which are to be ground, from an entrance slit of the grinder in the grinding grooves (60, 66, 90, 96) through the grinding slit to an exit slit, and to comminute them by means of the first grinding surfaces (64, 69) of the first grinding disk, wherein each first grinding surface (64, 69) of the first grinding disk is arranged such that it defines one of the grinding grooves (60, 66) of the first grinding disk at a rear side of the respective grinding groove (60, 66) relative to the grinding direction, - wherein each first grinding surface (64, 69) of the first grinding disk encompasses an angle of inclination φ at an arbitrary point at the respective first grinding surface (64, 69), relative to a tool reference plane (E-I), measured at an assumed working plane (E-II) in the grinding direction of the respective first grinding surface (64, 69), - wherein the tool reference plane (E-I) is a plane in the arbitrary point, which is embodied parallel to the grinding direction and vertically to the axis of rotation, and wherein - the assumed working plane (E-II) is a plane, which is oriented parallel to the axis of rotation and parallel to the grinding direction, through the arbitrary point, and