detection magnetic body 510 may be installed within the liquid detergent residual amount detection buoyancy body 500 a and configured to generate a magnetic field the liquid detergent residual amount detection buoyancy body 500 a may be hingedly coupled to one side of the main body 100 through a connecting arm 520 the liquid detergent residual amount detection buoyancy body 500 a may swing about a hinge by the buoyancy exerted by the liquid detergent contained in the liquid detergent storage part 110 a residual amount detection sensor 600 may be installed on the outer surface of the main body 100 in a position facing the liquid detergent residual amount detection buoyancy body 500 a in this case the residual amount detection sensor 600 may be a liquid detergent residual amount detection sensor 600 a see fig4 the liquid detergent residual amount detection sensor 600 a may sense approach of the liquid detergent residual amount detection buoyancy body 500 a more specifically the liquid detergent residual amount detection sensor 600 a may sense the magnetic field of the liquid detergent residual amount detection magnetic body 510 that is installed within the liquid detergent residual amount detection buoyancy body 500 a thus it can sense the approach of the liquid detergent residual amount detection buoyancy body 500 a without contacting the liquid detergent residual amount detection buoyancy body 500 a fabric softener may be stored in the fabric softener storage part 120 a fabric softener residual amount detection buoyancy body 500 b may be installed in a lower portion of the fabric softener storage part 120 in this regard a fabric softener residual amount detection magnetic body 510 configured to generate a magnetic field may.