A photosensitive polyimide resin precursor composition capable of providing a
polyimide
resin that is not substantially colored, is transparent and has heat resistance,
an optical polyimide resin obtained from the composition, and an optical waveguide
using the polyimide resin. The photosensitive polyimide resin precursor composition
contains (a) 100 parts by weight of a polyamic acid obtained from a tetracarboxylic
acid dianhydride and a diamine, (b) 0.01 parts by weight or more and less than
5 parts by weight of a 1,4-dihydropyridine derivative, (c) 5-50 parts by weight
of a glycol (ether). The optical polyimide resin is obtained by irradiating the
photosensitive resin precursor composition with UV light, followed by exposure,
heating, development, and then heating. The optical waveguide comprises a core
layer comprising the optical polyimide resin, and a cladding layer thereof.