A photodiode array with reduced optical crosstalk and an image pickup device using it are provided. The photodiode array 10 according to the present invention has an anti-crosstalk portion B dividing each adjacent pair of photodiodes S, the anti-crosstalk portion B and the photodiodes S individually have a p-type area 16 extending inward from the surface side of a semiconductor laminate, and the inner end of the p-type area of the anti-crosstalk portion, namely the front, is closer to the back surface of the semiconductor laminate than the front of the p-type area of each of the photodiodes.