A method of manufacturing a light emitting device , the method comprising: disposing a first semiconductor laser element on a disposition surface of a base member such that a light emission end surface of the first semiconductor laser element is parallel to a first line passing through a pair of alignment marks provided on the base member ; and disposing a first light-reflective member on the disposition surface such that a reference line (SL) for the first light-reflective member , which serves as an alignment reference in disposing the first light-reflective member , is parallel to a second line that is oblique to the first line at a predetermined angle; characterized in that the method further comprises: disposing a second semiconductor laser element on the disposition surface such that a light emission end surface of the second semiconductor laser element is parallel to the first line , and such that the first semiconductor laser element and the second semiconductor laser element are disposed symmetrically to each other with reference to a midpoint of the first line between the alignment marks ; and disposing a second light-reflective member on the disposition surface such that a reference line (SL) for the second light-reflective member is parallel to the second line , and such that the first light-reflective member and the second light-reflective member are disposed symmetrically to each other with reference to the midpoint of the first line . disposing a first semiconductor laser element on a disposition surface of a base member such that a light emission end surface of the first semiconductor laser element is parallel to a first line passing through a pair of alignment marks provided on the base member ; and disposing a first light-reflective member on the disposition surface such that a reference line (SL) for the first light-reflective member , which serves as an alignment reference in disposing the first light-reflective member , is parallel to a second line that is oblique to the first line at a predetermined angle; characterized in that the method further comprises: disposing a second semiconductor laser element on the disposition surface such that a light emission end surface of the second semiconductor laser element is parallel to the first line , and such that the first semiconductor laser element and the second semiconductor laser element are disposed symmetrically to each other with reference to a midpoint of the first line between the alignment marks ; and disposing a second light-reflective member on the disposition surface such that a reference line (SL) for the second light-reflective member is parallel to the second line , and such that the first light-reflective member and the second light-reflective member are disposed symmetrically to each other with reference to the midpoint of the first line . disposing a second semiconductor laser element on the disposition surface such that a light emission end surface of the second semiconductor laser element is parallel to the first line , and such that the first semiconductor laser element and the second semiconductor laser element are disposed symmetrically to each other with reference to a midpoint of the first line between the alignment marks ; and disposing a second light-reflective member on the disposition surface such that a reference line (SL) for the second light-reflective member is parallel to the second line , and such that the first light-reflective member and the second light-reflective member are disposed symmetrically to each other with reference to the midpoint of the first line . <EOS>