A tracking type laser interferometer that detects displacement of a retroreflector 300 being an object to be measured by utilizing interference of a laser beam 102 irradiated onto the retroreflector 300 and reflected by the retroreflector 300 in the returning direction, and carries out tracking by means of a two-axis turning mechanism 240 using displacement in the position of the optical axis of the laser beam 102; the same tracking type laser interferometer, includes; a light irradiator 600 that emits a fan-shaped laser light 602 that is fan-shaped including the optical axis of the laser beam 102, is interlocked with turning movements of the two-axis turning mechanism 240 around an axis orthogonal to the center axis of the corresponding fan shape; and a light receptor 620 that has a specific positional relationship with the retroreflector 300 or the light irradiator 600 and receives the fan-shaped laser light. Thereby, tracking can be automatically reset when the tracking is disabled due to a reason such as interruption of laser light or initial adjustment work can be automated when commencing measurement.