PURPOSE: To prevent high level noise from being produced even in the case of high sensitivity by selecting high resolution or high sensitivity optionally.

CONSTITUTION: Picture element separation electrodes 20 are arranged to prevent leakage of a charge between picture elements PS arranged in 2-dimension and controlled independently in the unit of m×n sets of picture element blocks. A separation electrode row selection circuit 31 and a separation electrode column selection circuit 32 move a charge between picture elements of m×n sets of picture element blocks in the case of processing high sensitivity to suppress the separation function of the plural picture element separation electrodes PS so as to collect the charge of surrounding picture elements to the read picture element.