The endoscope system 1 detects an abnormality of an image pickup signal from the image pickup device 10, an image pickup device 10 for picking up an image of the subject, an image pickup device 10 for initializing and driving the image pickup device 10, and drives an initialization start signal. And a monitoring unit 17 for outputting to the control circuit 19. The monitoring unit 17 compares the synchronization code, the optical black pixel value, and the effective pixel value of the imaging signal from the imaging device 10 with the threshold value indicating the normal range and the specified number of times or the specified number, and the synchronization code, the optical black pixel When an abnormality in either the value or the effective pixel value is detected, an initialization start signal is output to the drive control circuit 19, and the drive control circuit 19 receives the initialization start signal from the monitoring unit 17, The image sensor 10 is initialized again. 内視鏡システム１は、被写体を撮像する撮像素子１０と、撮像素子１０を初期化および駆動する駆動制御回路１９と、撮像素子１０からの撮像信号の異常を検知し、初期化開始信号を駆動制御回路１９に出力する監視部１７とを有する。監視部１７は、撮像素子１０からの撮像信号の同期コード、オプティカルブラック画素値、及び、有効画素値をそれぞれの正常範囲を示す閾値及び規定回数もしくは規定個数と比較し、同期コード、オプティカルブラック画素値、及び、有効画素値のいずれかの異常を検知した場合、初期化開始信号を駆動制御回路１９に出力し、駆動制御回路１９は、監視部１７から初期化開始信号が入力された場合、撮像素子１０の初期化を再度行う。
