Abstract: A device for trapping insects such as mosquitoes efficiently by gathering and concentrating them and conducting them into a suction inlet. The insect trapping device comprises: a carriage; a post standing on the carriage; a housing bulging forward over the post for sucking and trapping an insect; a suction inlet formed in the bottom face of the front of the housing; and an attractive element disposed below the suction inlet and on the carriage for attracting the insect. A gas cylinder is housed in the post and contains an attractive gas to be emitted from the attractive element. The attractive element is an upward protrusion with a black surface. An ultraviolet emitter is arranged near the suction inlet and emits a ray downward of the housing.