A mask apparatus includes a mask body including a rear body and a front body coupled to a front surface of the rear body and providing an inlet and an outlet, a face guard coupled to the rear body and defining a respiration space, and an air cleaning module purifying air introduced into the inlet and supplying the purified air to the respiration space. A portion of the rear body defines an accommodation portion accommodating the air cleaning module. The air cleaning module includes a fan module disposed at a seating portion of the accommodation portion, a filter disposed at a rear side of the fan module and purifying air flowing into the fan module, and a filter housing including a filter frame surrounding a side surface of the filter and a filter cover covering a rear surface of the filter. The inlet is provided at the filter cover.