A laundry drying machine includes: a cabinet, a drum rotatably disposed in the cabinet and configured to accommodate a target object, an electric field generator spaced apart from the drum and configured to, based on power being applied to the electric field generator, generate an electric field, and an exhaust duct configured to discharge air inside the drum. The electric field generator includes: (i) an anode electrode spaced apart from the drum, fixed to the cabinet, and configured to apply the electric field to the target object, (ii) a power supply unit configured to supply the power to the anode electrode, and (iii) a matcher configured to match a source impedance of the power and an impedance of a load side. The drum is configured to, based on a reflectivity of the electric field exceeding a predetermined ratio, reduce a rotation speed.