A portable air purifier is provided that may include a housing having an inlet forming a passage through which air is suctioned into the housing, a filter disposed at an upper side of the inlet and configured to purify air suctioned in through the inlet and flowing upward, an irradiator disposed at a lower side of the filter, installed at a height at which the irradiator overlaps the inlet and configured to irradiate light for sterilization onto the filter, and a sterilizer support configured to support the irradiator and configured to be fixed to the housing and disposed around an outer perimeter of the irradiator.