A mask manufacturing method includes a step of providing a metal substrate having a plurality of virtual zones on its surface, using a plurality of nozzles to spray an etching solution on the surface, wherein the virtual zones include a first and a second zone, and the metal substrate has a first thickness and a second thickness respectively in an unit area of the first zone and the second zone, wherein the first thickness is greater than the second thickness; the step of using the nozzles to spray the etching solution on the surface further includes respectively using a first spraying pressure and a second spraying pressure to spray the etching solution on the first zone and the second zone, and the first spraying pressure is greater than the second spraying pressure. The invention also provides a mask manufacturing device.