A polarization-maintaining optical fiber component which suppresses coupling of propagating light to a high-order mode at the optical coupling section of the polarization-maintaining optical fiber component, caused by different refractive indexes between the stress applying sections and the cladding, thus reducing excess loss, is constructed by using a polarization-maintaining optical fiber having stress applying sections arranged symmetrically to each other with respect to a core in a cladding surrounding the core, wherein the largest one of those concentric circles of the core or the said cladding which do not reach the stress applying sections and do not include the stress applying sections within has a diameter of 20 m or greater.