In this paper, a solar collector utilizing electro−hydro-dynamical(EHD) effect is proposed for improvement of the collector efficiency. The EHD solar collector is cylindrical and a double structure made of glass. Between the outer cylinder and the inner cylinder, there are black round stones for thermal storage and R123 as heat transporting medium is supplied in the inner cylinder. Two line electrodes are arranged at upside of the surface of R123 and the top of the outer cylinder is covered by a disk electrode made of copper. On the disk electrode, a heat exchanger is put. By applying direct high voltage between the electrode, corona wind occurs in the vapour of R123. In result, we are able to expect heat transfer enhancement from the collector toward the heat exchanger and improvement of collector efficiency.