To provide an optical interference measuring device of a multichannel type at low cost without incurring an increase in device size.SOLUTION: A first return light received by a first measurement head is guided to a detector via a first optical path and a fiber coupler, and a second return light received by a second measurement head is guided to a detector via a second optical path and a fiber coupler. The optical path length D1 from the fiber coupler to the tip of the first measurement head, the optical path length D2 from the fiber coupler to the tip of the second measurement head, the maximum optical path length R1max in the measurement range of the first measurement head, the optical path length S1 of first reference light interfered with the first return light, and the optical path length S2 of second reference light interfered with the second return light are set so as to satisfy the relationship D1+R1max-S1