Abstract: The present invention relates to technology for detecting three-dimensional motion of an object in a non-contact manner, at high speed, and with comparatively high precision. A speed detection section 11 detects speed of an object using a first laser beam 111 that is irradiated towards an object 100, and is reflected by the object 100. A distance detection section 12 detects speed of the object 100 using a second laser beam 121 that is irradiated towards the object 100, and is reflected by the object 100. The second laser beam 121 is configured to be irradiated at substantially the same time and to substantially the same position as the first laser beam 111. A motion calculation section 13 calculates motion of the object 100 using information on orientation of the first and second laser beams, the speed, and the distance.