The invention relates to a device for coating a substrate (14) using CVD, in particular for coating with diamond or silicon, wherein a heat conductor array comprising a plurality of elongated heat conductors (2) is provided in a housing (10), said heat conductors extending between a first (1) and a second electrode (8), wherein the heat conductors (2) are held individually tensioned by a tensioning device attached to one end thereof. For the purposes of improving the life of the heat conductors (2), the invention proposes that the tensioning device comprises a tilt arm (5) having a tensioning weight (G), the heat conductor (2) being attached to the first end (E1) of said tilt arm, and the second end thereof substantially being mounted pivotably about a horizontal axis (H).