a method of manufacturing a laser diode array capable of inhibiting electric cross talk is provided . the method of manufacturing a laser diode array includes a processing step of forming a peel layer containing an oxidizable material and a vertical resonator structure over a first substrate sequentially from the first substrate side by crystal growth , and then selectively etching the peel layer and the vertical resonator structure to the first substrate , thereby processing into a columnar shape , a peeling step of oxidizing the peel layer from a side face , and then peeling the vertical resonator structure of columnar shape from the first substrate , and a rearrangement step of jointing a plurality of vertical resonator structures of columnar shape obtained by the peeling step to a surface of a metal layer of a second substrate formed with the metal layer on the surface .