Provided is an optical switch element capable of adjusting an output strength of light output from an optical switch to a fixed level. The optical switch element includes: an optical coupler configured to divide an input light into N fractions of light and output the N fractions of light, where N represents an integer equal to or larger than 2; N branch optical waveguides connected to an output side of the optical coupler; N light absorption gates connected to the respective N branch optical waveguides; and N output optical waveguides connected to the respective N light absorption gates, the optical coupler, the N branch optical waveguides, the N light absorption gates, and the N output optical waveguides being connected to one another in order, the N light absorption gates each being controlled to adjust an output strength of transmitted light output from the N output optical waveguides based on a loss amount acquired in advance by a light absorption effect or light amplification effect of the N light absorption gates.