A non-contact power transmission device according to one or more embodiments is disclosed, which may include a fixed portion, a rotating portion that rotates about an axis, and a base cover including these. The fixed portion includes a first coil, a first substrate, and a light emitting element. The rotating portion includes a second coil, a second substrate, a light receiving element, and a case cover. The case cover is formed with a heat dissipation opening having an inclined surface, and generates airflow in which air is sucked into the inside of the case cover and is discharged to the outside of the case cover, as the rotating portion rotates.