A target supply device may include a tank configured to store a target substance, a pressure adjuster configured to adjust a pressure in the tank, a filter configured to filter the target substance in the tank, a nozzle configured to output a droplet of the target substance having passed through the filter, a droplet detector configured to detect outputting of the droplet from the nozzle, and a processor configured to control the pressure adjuster so that a pressure-increasing speed of the pressure in the tank is higher after detection of outputting of the droplet than before detection of outputting of the droplet, during a period in which the pressure in the tank is increased to a target pressure from a pressure at which outputting of the droplet is detected by the droplet detector for the first time after installation of the target supply device.