An inspection method for a circuit substrate is disclosed, which inspects electrical properties of a circuit substrate having a multilayered structure, by controlling inspection environments so that dew forms on a surface of the circuit substrate and detecting change of states of the dew to thereby determining variation of a thermal capacity of a conductor with respect to defective contacts or vias, micro vias and a circuit pattern of an inner layer. According to this, the inspection can be performed with respect to a wide area simultaneously and therefore the inspection productivity can be improved. In addition, since the temperature of the conductive wire can be measured directly through change of the dew, the cost for the temperature measurement can be saved. Moreover, the cost for an area sensor to sense the temperature of a wide area may be reduced while improving the inspection speed.