The invention concerns a panel of a flooring system, in particular a laminate floor, with a first side edge, and with a second side edge which is arranged opposite the first edge, wherein the side edges can be locked with corresponding side edges of further panels, wherein the side edges can be brought into engagement with each other, wherein the first side edge is fitted with at least one locking lip, and with an elasticity groove adjacent to the locking lip, wherein the second side edge is fitted with a locking element and wherein the locking element in the locked state is in engagement with the locking lip. To be able to set the elasticity of the locking lip more satisfactorily, it is provided that the elasticity groove is at least partly filled with at least one filling compound.