To provide an LED illumination unit and an illumination fixture wherein characteristics are improved without inviting large-sizing or cost-up.

The LED illumination unit B is equipped with a substrate 1 on which an LED chip 2 is mounted and a retaining member 4 to retain a lens part 3 which controls light distribution of light irradiated from the LED chip 2. In the retaining member 4, then nearly disc form bottom part 4a and a side part 4b which extends out upward across the whole periphery from the outer edge of the bottom part 4a are integrally formed. The nearly hemispheric lens part 3 is integrally formed at the nearly center position of this bottom part 4a, and a convex lens face 3a which protrudes to the substrate 1 side is installed at the substrate 1 side site of the lens part 3. Moreover, 4 pieces of nearly triangular heat dissipation holes 4c are penetratingly installed at an equal angle along the peripheral direction at the bottom part 4a, and the rectangular heat dissipation holes 4d are penetratingly installed respectively at positions corresponding to the respective heat dissipation holes 4c at the side part 4b. Then, the retaining member 4 is mounted on the fixture main body 6 of the illumination fixture A in a direction that the bottom part 4a becomes the lower side.