Disclosed is a sterilizing apparatus for footwear. The sterilizing apparatus includes a plane heater having a carbon fiber embedded heating paper, a pair of electrodes installed at one side of the carbon fiber embedded heating paper while being spaced from each other, and insulating members stacked on upper and lower portions of the carbon fiber embedded heating paper and edge portions of which are thermally bonded to each other; a housing made of a flexible material and formed at an inner peripheral portion thereof with an insertion groove, in which the housing has a power line receiving hole at a lower end of a bottom surface thereof, a cation generating material receiving hole, and a plurality of corrugated grooves; an AC/DC converter having a time display section and a timer setting section; and a cation generating material fixedly inserted into the cation generating material receiving hole by adhesive.