Provided is a dry reagent that allows measuring with good precision, in accordance with a transmission method that utilizes light of the ultraviolet region, increases or decreases of a nicotinamide coenzyme, in order to quantify a component contained in a liquid sample.A dry reagent 4 for performing a quantitative analysis of a specific component in a liquid sample S contains a nicotinamide coenzyme and a leveling agent for smoothing the dry reagent 4. Increases or decreases of the nicotinamide coenzyme are measured in accordance with a transmission method that utilizes light of the ultraviolet region. The leveling agent is a combination of an alkali and at least one type selected from among a saccharide and a surfactant.