This invention provides an optical film having a reduced thickness and an increased width, which is free from bleedout with the elapse of time (during storage) in a continuous wound state, a method for manufacturing an optical film, and a polarizing plate using the optical film. The optical film is a plasticizer-containing optical film having an overall width of 1500 mm to 4000 mm produced by a solution casting method. The amount of the plasticizer present in the center portion in the surface side of the optical film is determined as value A by TOF-SIMS. The amount of the plasticizer present in the center portion in the back side is determined as value B by the TOF-SIMS. Value X is determined by formula 1 based on the values A and B. The amount of the plasticizer present in the end portion in the surface side of the optical film is determined as value A′ by TOF-SIMS, and the amount of the plasticizer present in the end portion of the back side is determined as value B′ by the TOF-SIMS. Value X′ is determined by formula 2 based on the values A′ and B′. The X value is different from and larger than the X′ value.