A method for producing a colorless transparent resin film by a solution flow casting method containing: flow-casting an organic solvent solution of a polyamic acid or a polyimide on a support; and drying, the method containing at least the following step (1), step (2) and step (3) in this order, and an apparatus therefor: (1) a step of flow-casting an organic solvent solution of a polyamic acid or polyamide on a support, (2) a step of evaporating the organic solvent while blowing a gas having an oxygen content of from 0.001 to 15% by volume at a temperature of from 100 to 170° C. onto the flow-cast material, and releasing as a self-supporting film from the support, and (3) a step of performing the following step (3-1) and step (3-2) in this order: (3-1) a step of lowering a residual ratio of the organic solvent in the self-supporting film while blowing a gas having an oxygen content of 15% by volume or less at a temperature of from 100 to 250° C. onto the film by using at least one dryer of a type of blowing a heated gas, and (3-2) a step of lowering the residual ratio of the organic solvent in the self-supporting film while blowing a gas having an oxygen content of 5% by volume or less at a temperature of from 150 to 400° C. onto the film by using at least one dryer of a type of blowing a heated gas.