An object of the disclosure is to provide a glass panel and a glass window which are configured to stably maintain a depressurized space therein even when their spacers contain a resin. A glass panel unit of an aspect of the disclosure includes: a first glass pane; a second glass pane facing the first glass pane; a frame member which has a frame shape and which the first and second glass panes are bound together through; and spacers containing a resin and disposed between the first and second glass panes. A depressurized space is provided between the first glass pane and the second glass pane. The first and second glass panes are respectively to be exterior and interior panes. The first glass pane has lower ultraviolet transmittance than the second glass pane.