There is provided a solid-state image pickup device including: a pixel array portion which includes a plurality of unit pixels each having a photoelectric conversion element and an output transistor for outputting a signal according to charge obtained by photoelectric conversion of the photoelectric conversion element; a comparing portion which compares the signal output from each of the unit pixels with a ramp-shaped reference signal; a measuring portion which starts an operation in synchronization with the supply of the reference signal to the comparing portion, performs the operation until the comparison output of the comparing portion is inverted, and measures a time until the comparison of the comparing portion is finished; and a detecting portion which detects a predetermined image pickup condition and fixes the comparison output of the comparing portion to a state before the comparison starts when the image pickup condition is detected.