According to one embodiment, a semiconductor light emitting device includes a stacked structure body, first and second electrodes. The stacked structure body includes first and second semiconductor layers and a light emitting layer provided between the second and first semiconductor layers, and has first and second major surfaces. The first electrode has a first contact part coming into contact with the first semiconductor layer. The second electrode has a part coming into contact with the second semiconductor layer. A surface of the first semiconductor layer on a side of the first major surface has a first part having a part overlapping a contact surface with the first semiconductor layer and a second part having a part overlapping the second semiconductor layer. The second part has irregularity. A pitch of the irregularity is longer than a peak wavelength of emission light. The first part has smaller irregularity than the second part.