An optical characteristic of a coupled multi-core optical fiber is evaluated without core alignment, one of plural cores thereof being arranged as a center core at the center of a cladding thereof, a total number of spatial modes being a number of the cores or greater, (a fiber length)×(a power coupling coefficient between the cores) being 10 or greater. The coupled multi-core optical fiber is joined to a dummy fiber, having a core at the center of a cladding having the same shape and dimension as those of the coupled multi-core optical fiber, by causing one ends of the fibers to face each other and aligning the fibers with reference to the circumferences of the fibers. Light is launched to the coupled multi-core optical fiber joined to the dummy fiber, and a light measurement unit measures the light passing through the fibers.