Provided is a motion vector detecting apparatus capable of detecting a motion vector based on each of front and rear frames as a starting point while restraining an increase of a circuit scale. A starting pixel generation unit generates starting pixel data based on pixel data in a frame f0 or a frame f1. A search range pixel generation unit generates search range pixel data based on pixel data in the frame f1 or the frame f0. Switches alternately switch the frames f0 and f1 at every line. A motion vector selection unit generates alternately a motion vector based on the frame f0 as a starting point and a motion vector based on the frame f1 as a starting point. A correlation comparing unit selects one motion vector having higher correlation between the motion vectors.