A cooling apparatus includes a coolant passage provided in a device to be cooled. The coolant passage is configured in such a manner that coolant passes through the coolant passage. The coolant passage includes a wall surface, first ribs, and second ribs. The first ribs and the second ribs are provided on at least a part of the wall surface. The first ribs protrude from the wall surface toward inside of the coolant passage and extend in a first direction. The second ribs protrude from the wall surface toward the inside of the coolant passage and extend in a second direction crossing the first direction. The first ribs and the second ribs are disposed alternately when viewed in at least one direction.

A cooling apparatus includes a coolant passage provided in a device to be cooled. The coolant passage is configured in such a manner that coolant passes through the coolant passage. The coolant passage includes a wall surface, first ribs, and second ribs. The first ribs and the second ribs are provided on at least a part of the wall surface. The first ribs protrude from the wall surface toward inside of the coolant passage and extend in a first direction. The second ribs protrude from the wall surface toward the inside of the coolant passage and extend in a second direction crossing the first direction. The first ribs and the second ribs are disposed alternately when viewed in at least one direction.