A method for manufacturing a glass panel unit includes an assembling step, a gas exhausting step, and a sealing step. At least one of a first glass pane or a second glass pane includes a low-emissivity film. In a situation where the low-emissivity film is heated at a temperature increase rate of 4° C./min before a peripheral wall is melted, a ratio of an emission quantity of a rare gas emitted from the low-emissivity film at a deformation temperature of the partition to an emission quantity of the rare gas emitted from the low-emissivity film at 100° C. is equal to or less than 2.0.