To secure bit resolution of a low dose region without using an AD converter of a high bit in a picture reading method and a picture reader, with which current outputted from a solid detector is detected, an analog signal corresponding to an amount of current is converted into a digital signal and a picture signal is created.

A current detecting means 20 detects current outputted from the solid detector 10 by a plurality of different gains G at every pixel. An AD conversion means 30 converts the analog signal corresponding to the amount of the currents detected by the plurality of different gains G into the digital signal. A picture signal creating means 40 selects the digital signal corresponding to the largest gain G when the digital signal which is not saturated exists from the digital signals corresponding to the respective gains G at every pixel, selects the digital signal among them when the digital signal which is not saturated does not exist and creates a picture signal based on the selected digital signal.