The present invention pertains to a method of fabricating a polarizing film by uniaxially stretching a resin film such as a polyvinyl alcohol-based film in a fabrication process including a swelling step and a dyeing step following the swelling step, comprising the steps of immersing a resin film in bath liquids in at least two or more swelling baths in sequence in the above-mentioned swelling step, wherein at least a bath temperature of a swelling bath located at a Nth position from the front-stage side is set at a temperature which is higher than a bath temperature of a swelling bath located at a (N+M)th position by 3.degree. C. or more (both N and M are specified positive integers).