PURPOSE: To realize an Si light-emitting device which is provided with a new constitution by a method wherein a porous Si region as well as an n-type region and a p-type region which sandwich it are formed on an Si layer on an SOI substrate.

CONSTITUTION: A p-type Si layer 3 is arranged on an Si support substrate 1 via an SiO2 film 2, an SOI substrate 4 is constituted, the Si support substrate 1 and the Si layer 3 are provided respectively with a (100) plane, silicon nitride is deposited on the whole surface, a stripe-shaped opening part 5 is formed in a prescribed position, and the SOI substrate 4 is immersed in an aqueous HF solution. Then, the p-type Si layer 3 is exposed in the opening part 5, Au is sputtered from the rear side of the Si support substrate 1, a back contact electrode 6 is formed, an anodic oxidation operation is executed, and a porous Si region 8 is formed. Then, a CVD Si or CVD SiC layer 10 is deposited on it, impurities are ion-implanted into regions on both sides of the porous Si region 8, an n-type region 12 and a p-type region 13 are formed, and, thereby, a pin diode structure provided with a light-emitting region can be realized.