A method for producing a polymer optical waveguide including: (1)
preparing a template that is made of a template forming curable resin and
has a concave portion, (2) applying an ozone treatment or irradiating
light having a wavelength of 300 nm or less to at least one of a surface
of the template having the concave portion and a core formation surface
of a cladding film substrate, (3) bringing the cladding film substrate
into close contact with the template, (4) filling a core forming curable
resin into the concave portion of the template with which the cladding
film substrate is in close contact, (5) curing the filled core forming
curable resin to form a core, (6) removing the template from the cladding
film substrate, and (7) forming a cladding layer on the cladding film
substrate on which the core has been formed.