To reduce action resistance by performing the work of manufacturing a diode where the thickness of one layer is changed with the thickness of the other layer of a quantum wave interfering layer fixed, and getting the range of the thickness of one layer which shows the vicinity of the minimum value of operation resistance for each thereby deciding the thickness of each layer.

An electron reflective layer 20 being a quantum wave interfering layer is made fifteen cycles of multiple quantum structure using p-Ga0.51In0.49P for the first layer and p-Al0.51In0.49P for the second layer. The thickness of each layer of this electron reflective layer 20 is decided by the work of manufacturing diode, where the thickness of the first layers is changed with the thickness of the second layer fixed severally, and getting the thickness of the first layer which shows the vicinity of the minimum value of operation resistance and the work of manufacturing diodes where the thickness of the second layers is changed with the thickness of the first layer fixed severally, and getting the thickness of the second layer which shows the vicinity of the minimum value of operation resistance. As a result, the thickness of the first layer and the second layer is optimized, whereby the operation resistance can be dropped.