To properly measure speed based on imaged image information.

The speed measuring device includes an imaging means 2, having an imaging element equipped with a plurality of pixels; a position information detecting part 32 the for detecting an image information position which is a position in a pixel array on the imaging element of pixels from which a plurality of imaged pieces of image information are extracted; an imaging range calculating part 33 for calculating the imaging range of the plurality of pixels; a moving distance calculating part 34 for calculating the moving distance in each image information, relative to the plurality of pieces of image information based on the imaging range of each pixel and on each image information position, before and after the lapse of a prescribed time; and a speed information calculation part 35 for calculating speed information based on each moving distance of the plurality of pieces of image information.