The passive electric potential CT method was applied to identification of plural delaminations in a composite material. The piezoelectric film was pasted on the surface of CFRP composite material subjected to three-point bending. The effect of the location of delaminations on electric potential on piezoelectric film was investigated. A hierarchical inversion scheme was proposed for identification of plural delaminations. Numerical simulations were made to investigate the possibility of identification of delaminations from electric potential on the piezoelectric film. It was found that it was possible to identify the delaminations by the present method.