To provide a panel unit needing little time and labor for after- execution and improved in appearance.

A panel unit 8 with a waterproof sheet is formed having a plate-like panel body 15 with cutout parts 15A formed at four corners so as to be used at the time of jointing the panel unit 8 to a building body, and the waterproof sheet 16 having almost triangular folded parts 16A at four corners and fixed to the upper face of the panel body 15 at the remaining part excluding the folded parts 16A. The folded part 16A is formed into such a size as to cover the cutout part 15A of the panel body 15.