An illumination light guiding device includes a phosphor layer that is disposed on another surface opposite to one surface of a board, and converts the wavelengths of a plurality of light beams transmitted through the board and incident on one surface of the phosphor layer, and an emission-side fiber including a plurality of optical fibers that are provided so as to be erected side by side on another surface opposite to one surface of the phosphor layer, each optical fiber guiding a different one of the plurality of light beams having wavelengths converted by the phosphor layer.
