The present invention relates to a positive charging single-layer type electrophotosensitive material comprising a conductive substrate and a photosensitive layer formed on the conductive layer, the photosensitive layer containing a phthalocyanine compound as an electric charge generating material, wherein a large half-life exposure between a half-life exposure on positive charging and a half-life exposure on negative charging is four times or less as much as that of the other half-life exposure., and a reversal development type digital image forming apparatus, comprising the electrophotosensitive material, said reversal development type digital image forming apparatus being provided with at least a main charging step, an exposure step, a developing step, a transferring step, a charge neutralizing step and a cleaning step in the forward direction of the electrophotosensitive material, characterized in that the voltage to be applied in the transferring step has a polarity reverse to that of the voltage to be applied in the charging step.