The present invention aims to provide a light wave distance meter which can deal with an extremely large amount of reflected light and precisely measure a distance to a measuring target object. The light wave distance meter (10) irradiates a measuring target object (11) with measuring light (Pm) and a light receiving element (23) receives measuring light (Pr) reflected by the measuring target object (11) to obtain a round-trip time from the measuring light to the measuring target object (11) and measure the distance to the measuring target object (11). The light wave distance meter includes a light receiving optical system (19) which receives and condenses the measuring light reflected by the measuring target object (11), and a transmission optical path unit (21) which transmits the measuring light condensed by the light receiving optical system (19) to the light receiving element (23), including a multi-mode graded index fiber (26) and a multi-mode step index fiber (27) coupled with each other.