A method of manufacturing an electron-emitting device has a step of forming a pair of conductors on a substrate, the conductors being spaced from each other, and an activation process of depositing carbon or carbon compound on at least one side of the pair of conductors in an atmosphere of carbon compound gas. The activation process includes a plurality of processes of two or more stages including a first process and a second process. The first process is executed in an atmosphere of the carbon compound gas having a partial pressure higher than a partial pressure of the gas in the second process, with the second process being the last activation process.