The present invention relates to an apparatus and a method for exterminating pests by injecting high-temperature steam into the ground including sand and the like, wherein a needle rod fixing plate (20) in which a plurality of needle rods (30) is arranged and fixed at the left and right sides thereof is coupled with a lever plate (12) rotated upward and downward by an operating cylinder (10) at a backside of autonomous power equipment (2), a steam generation unit (16) is provided to generate high-temperature steam enabling insect extermination and sterilization and supply the steam to steam injection holes (36) of the needle rods (30), a steam generation unit (16) and a needle rod (30) are connected by a hose, a steam distributor (44-1, 44-2) for supplying the steam to each needle rod (30) is provided on the hose, both ends of the steam distributor (44-1, 44-2) are coupled with a cover (48) so as to be sealed, a heating wire (49) for increasing the temperature of the steam again is provided therein, the needle rods (30) are inserted and moved forward in the bowels of the earth (6) by operating the autonomous power equipment (2), and a pest extermination operation unit (4) includes a control unit (80) for controlling the continuous injection of steam into the ground (6) so as to exterminate insects and sterilize the ground by enabling the dry or wet high-temperature steam to continuously permeate into the ground.
