To provide a cleaning method, a cleaning chemical, and a cleaning device that exhibits high performance for removing particles on a substrate, and to provide a semiconductor device.

The cleaning method of a substrate includes a first process for adjusting the concentration of dissolved nitrogen in demineralized water to the equilibrium concentration of dissolved nitrogen with air (approximately 16 ppm) or lower on a demineralized water supply line for supplying the demineralized water, and a second process for supplying a cleaning chemical that is prepared by mixing the demineralized water adjusted by the first process with at least hydrogen peroxide water to a cleaning tank, and for applying an ultrasonic wave to the cleaning chemical in which the substrate is dipped for cleaning.