Female Plodia interpuctella Hubner was cheesed as a material and its sex pheromone glands were observed by light microscope and electron microscope. 1. In morphology Pheromone gland cells were various from the cuboid, around 3 micron in length, to column, around 14 micron in length, and these cells were arranged with monolayer. 2. Lumen wall was covered with the bilayered cuticle in accordance with the staining degree. 3. Starting from apodeme 6 to 6.3 micron in diameter, the pheromone gland was connected with both sides of abdomen muscle. 4. Pheromone gland between 8th and 9th segments was inveginated in the 8th segment, and judging from its total view its shape was like "ring". Especially in the lower side it was considerably deeply rooted with an estimated sixty micron in length in comparision with the other parts. 5. Cell cytoplasm of pheromone gland connected with the cuticle layer showed the infolded phenomenon thoroughgoingly. 6. Cytoplasm had well-developed smooth endoplasmic reticulum, but few rough endoplasmic reticulum, and a few ribosomes, sometimes forming clutters 7. The phenomena of mitochondrial autolysis took place, accassionally, microtubule was well developed.