To provide a wavelength conversion film which is capable of maintaining an optical wavelength converting function for a long term as compared with conventional wavelength conversion films.A wavelength conversion film 1 comprising a single layered film consisting of a resin composition containing a thermoplastic resin 10, a wavelength converting material 12 and a specific nickel(II) dialkyldithiocarbamate 14, or a laminated film having a wavelength converting layer consisting of the resin composition, wherein the alkyl group of the specific nickel(II) dialkyldithiocarbamate 14 is an ethyl group or a butyl group, and the content of the specific nickel(II) dialkyldithiocarbamate 14 is from 20 to 250 parts by mass per 100 parts by mass of the wavelength converting material 12.
