A signal processing circuit of a solid-state imaging element which processes a signal of the solid-state imaging element having a first pixel group and a second pixel group in which a charge accumulation time or photosensitivity is different by α times from that of the first pixel group, includes a calculation unit that multiplies a signal value of a pixel of interest in the first pixel group by α times, a weighting unit that performs weighting with respect to the signal value of the pixel of interest based on a signal value of a pixel associated with the pixel of interest, and a synthesis unit that synthesizes the signal value which has been multiplied by α times in the calculation unit and on which the weighting has been performed in the weighting unit and a signal value of a pixel of the second pixel group.