There is provided a ZnO based compound semiconductor light emitting device which can emit light with high efficiency and from an entire surface while using ZnO based compound semiconductor which can be expected with higher light emitting efficiency than that of a GaN based compound. On an insulating substrate (1), an n-type layer (2), an active layer (3), and a p-type layer (4), made of ZnO based compound semiconductor materials, are laminated, wherein a specific resistance of the n-type layer is 0.001 Ω·cm or more and 1 Ω·cm or less, and a film thickness (μm) of the n-type layer is set in a value or more calculated by a formula (specific resistance (Ω·cm))×300, and an n-side electrode (5) is formed on an exposed portion of a surface of the n-type layer opposite to a surface being in contact with the substrate and a p-side electrode (6) is formed on the p-type layer.