A terahertz wave detection device includes a low-dimensional electron system material formed on a substrate; and a first electrode and a second electrode opposingly arranged on a two-dimensional plane of the low-dimensional electron system material. The first electrode and the second electrode are made of metals having different thermal conductivity. An 8-element array sensor includes eight terahertz wave detection devices aligned in an array. The terahertz wave detection device includes carbon nanotube film; a first electrode disposed on one side of the carbon nanotube film; and a second electrode disposed on the other side of the carbon nanotube film. The first electrode and the second electrode have different thermal conductivity.