To provide a fluoropolymer suitable for use as a base polymer for resist materials for excimer lasers having a wavelength of 250 nm or shorter. A multilayer wiring board includes a multilayered construction where a plurality of resin insulating layers and a plurality of conductor layers are alternately layered. The optical device comprises a wavelength-selective optical tap that selectively drops a first portion of the optical power of a received optical signal having a specific wavelength.