The present invention discloses a total layer thickness detection apparatus for a charged body including: a saturated charge amount detection unit that detects a saturated charge amount of a charged body having plural coating layers with mutually different relative dielectric constants; a storage unit that stores relation information indicating relation of change of the saturated charge amount ofthe charged body with respect to a change of layer thickness of a surface layer of the charged body; and a calculation part that calculates a total layer thickness of the plural coating layers of thecharged body based on the change of the saturated charge amount detected by the saturated charge amount detection unit and the relation information stored in the storage unit.