PURPOSE: To restrain temperature rise in a front cover fitted to an electric motor-tricycle.

CONSTITUTION: A communicating hole 20a to the ceiling part inside the seat box 20 and a box-like cover 25 having an air introducing port 27 on the lower part are provided on the side of a seat box 20, a partition plate 28 is arranged on the upper part and rearward along the ceiling part to form an air flow passage communicated to the hole 20a, an air discharge port 29 is provided on the lower end of the seat box 20, and an electronic device 23 is mounted on the ceiling part. During running, wind flows to the electronic device 23 through the air introducing port 27, the hole 20a, and the electronic device 23 can be cooled. Further, because the air introducing port 27 and the air discharge port 29 are provided on the lower position, water jump can be prevented.