There is provided a polarizer having a non-polarization portion that can achieve the multi-functionalization and high-functionalization of an electronic device, such as an image display apparatus, the polarizer being excellent in dimensional stability and external appearance of the non-polarization portion. A polarizer according to an embodiment of the present invention includes a resin film containing a dichromatic substance, wherein: the polarizer has a non-polarization portion at a predetermined position; and the non-polarization portion includes a thin-walled portion thinner than another portion of the resin film.