A glass panel unit manufacturing method includes a bonding step, a pressure reducing step, and a sealing step. The bonding step includes bonding together a first substrate including a wired glass pane and a second substrate including a non-wired glass pane with a first sealant in a frame shape to create an inner space. The pressure reducing step includes producing a reduced pressure in the inner space through an exhaust port that the first substrate has. The sealing step includes irradiating the second sealant with an infrared ray externally incident through the second substrate to seal the exhaust port up with the second sealant that has melted.