A method for joining a plurality of material panels (10, 11) having a plurality of surfaces, wherein the surfaces of the material panels are formed by a plurality of mutually adjoining longitudinal edges (10a, 11a), transverse edges (10b, 11b) and faces (10c, 11c), wherein the faces adjoin the longitudinal edges (10a, 11a) and transverse edges (10b, 11b) and are of a larger surface area than the longitudinal edges and transverse edges, wherein the material panels (10, 11) are positioned precisely in relation to one another in a joining station, wherein at least one face preparation unit is arranged such that it is stationary and at least one of the surfaces that is to be joined is arranged such that it is movable for a relative movement in relation to one another, wherein the face preparation unit, comprising a heating blade, applies heat to at least one of the material panels (10, 11) and starts to melt it and thus prepares the at least one surface to be joined for joining, wherein the partially melted surfaces for joining are then bonded to one another by contact pressure in a substance-to-substance or force-locking bond, wherein the face preparation unit is guided in a direction normal to the direction in which the surface of the face (10c, 11c) of the at least one material panel (10, 11) extends, wherein at least one longitudinal edge and/or transverse edge of a first material panel is joined to at least one surface of a further material panel, wherein the material panels are pressed by contact pressure arrangements, and wherein the face preparation unit is guided in relation to the surfaces to be joined at an obtuse to right-angled angle of more than 45 degrees to the face (10c, 11c) of at least one material panel (10, 11), characterised in that the at least one surface to be joined is prepared for joining during the relative movement, in that the face preparation unit is guided in a joining gap in which a guiding blade is also arranged, in that the guiding blade is associated with the heating blade that is in contact with the material panels, in a leading position in respect of the joining procedure, upstream of the heating blade as seen in the feeding direction of the material panels, and in that the material panels are bonded in the joining station with monitoring of the contact pressure by sensor. wherein the material panels (10, 11) are positioned precisely in relation to one another in a joining station, wherein at least one face preparation unit is arranged such that it is stationary and at least one of the surfaces that is to be joined is arranged such that it is movable for a relative movement in relation to one another, wherein the face preparation unit, comprising a heating blade, applies heat to at least one of the material panels (10, 11) and starts to melt it and thus prepares the at least one surface to be joined for joining, wherein the partially melted surfaces for joining are then bonded to one another by contact pressure in a substance-to-substance or force-locking bond, wherein the face preparation unit is guided in a direction normal to the direction in which the surface of the face (10c, 11c) of the at least one material panel (10, 11) extends, wherein at least one longitudinal edge and/or transverse edge of a first material panel is joined to at least one surface of a further material panel, wherein the material panels are pressed by contact pressure arrangements, and wherein the face preparation unit is guided in relation to the surfaces to be joined at an obtuse to right-angled angle of more than 45 degrees to the face (10c, 11c) of at least one material panel (10, 11), characterised in that the at least one surface to be joined is prepared for joining during the relative movement, in that the face preparation unit is guided in a joining gap in which a guiding blade is also arranged, in that the guiding blade is associated with the heating blade that is in contact with the material panels, in a leading position in respect of the joining procedure, upstream of the heating blade as seen in the feeding direction of the material panels, and in that the material panels are bonded in the joining station with monitoring of the contact pressure by sensor.