An image sensor is disclosed. The image sensor includes a plurality of photodiodes arranged in first and second directions in a matrix, a plurality of first isolation layers, each two adjacent first isolation layers arranged in the first direction being spaced apart from each other by a first distance, each first isolation layer being interposed between adjacent photodiodes arranged in the second direction, and a plurality of second isolation layers, each two adjacent second isolation layers arranged in the second direction being spaced apart from each other by a second distance, each second isolation layer being interposed between adjacent photodiodes arranged in the first direction.