A solid-state imaging apparatus comprises first accumulation units, of which number is n, holding a digital value of n-bits output from a counter, second accumulation units, of which number is n, holding the digital value of n-bits transferred from the first accumulation units, of which number is n, and an A/D converter writing the digital value of n-bits from the counter based on an image signal generated by pixels into the first accumulation units, of which number is n, wherein correspondingly to each column of the pixels, the first accumulation unit of m-th bit (1≦m≦n) and the second accumulation unit of m-th bit (1≦m≦n) are arranged and paired, and the pairs of which number is n are arranged in a direction along the column of pixels.