A star sensor mounted in a satellite subjected to a spinning motion includes an optical system for obtaining an image of a fixed star, a CCD area sensor as an image pickup device arranged at a focal point of the optical system, a signal processing circuit for receiving an output from the CCD area sensor through a preamplifier, and a CCD driving circuit connected to the CCD area sensor. The CCD area sensor is an interline type CCD. The optical axis of the optical system is perpendicular to a spinning axis of the satellite. The horizontal scanning direction of the CCD area sensor coincides with the direction of the spinning axis. For this reason, the star image is moved on the light-receiving surface of the CCD area sensor along the vertical scanning direction with the spinning motion of the satellite. The CCD driving circuit causes the CCD area sensor to perform time-delay integration at a speed corresponding to the spinning speed of the satellite. After one-frame information obtained by the photoelectric transducer is transferred (frame shift) to the vertical transfer CCD arrays, only a one-horizontal line component is read out for a period between one frame shift and the next frame shift. Therefore, movement of the star image on the photoelectric transducer is synchronized with the transfer speed of the signal charge in the vertical transfer CCD arrays, and thus the signal charge of the star image can be integrated in the vertical transfer CCD arrays.