A solid state imaging device includes: an AD conversion section having one comparison section, which receives a reference signal from a reference signal generator that generates the reference signal whose level gradually changes and which compares the reference signal with an analog signal to be processed, and one counting section, which receives a count clock for AD conversion and performs a count operation on the basis of a comparison result of the comparison section, for each of M signal lines to which the signal is supplied and that acquires the signal on the basis of output data of the counting section; an operation period control section controlling an operation period of the counting section on the basis of the comparison result; and a control section performing control regarding which of the signals, which are supplied through the M signal lines, is to be processed and which one of m levels of the signals to be processed is to be processed and controlling the processing order.