A bonding method according to an exemplary embodiment of the present disclosure includes a first holding processing, a second holding processing, a temporary bonding processing, a temperature increasing processing and a main bonding processing. In the first holding processing, a target substrate is held. In the second holding processing, a glass substrate held by electrostatic adsorption. In the temporary bonding processing, the target substrate and the glass substrate are temporarily bonded with a pressing force lower than a predetermined pressing force at a temperature lower than a predetermined temperature. In the temperature increasing processing, while releasing the electrostatic adsorption of the glass substrate at the same time as or after the temporary bonding, the temperature is increased to the predetermined temperature. In the main bonding processing, a main bonding of the target substrate and the glass substrate is performed with the predetermined pressing force.