A method of inserting wooden or plastic connecting elements into at least one of end faces and longitudinal sides of technical wood products which are continuously conveyed along a device. The technical wood products have two opposing planar surfaces, the end faces connect the opposing planar surfaces and have a relatively small surface area compared to the two opposing planar surfaces. At least one of the end faces and the longitudinal sides have grooves for receiving the connecting elements. The method includes providing an inventory of pre-fabricated connecting elements. Cutting and separating the connecting elements and transferring the connecting elements from the inventory into magazines. Grasping individual ones of the connecting elements from the magazines with a transfer device and lifting or lowering the individual connecting element to the height of the groove in the technical wood products. Pressing the individual connecting element into the groove of the continuously conveyed technical wood products with a press-in unit in a program-controlled manner.