The optical transmission module 1 includes an optical element 10 having a light emitting unit that outputs light of an optical signal, a first main surface 20SA, and a second main surface 20SB, and the optical element 10 is provided on the second main surface 20SB. , A holding member 30 having a lower surface 30SB fixed to the first main surface 20SA of the wiring board 20 and having an optical fiber through hole H30 perpendicular to the lower surface 30SB, and an optical fiber An optical fiber 50 that transmits an optical signal inserted into the through hole H30, the first main surface 20SA of the wiring board 20 has a recess T20, and the holding member 30 is an adhesive inside the recess T20. It is fixed to the wiring board 20 via 40.光伝送モジュール１は、光信号の光を出力する発光部を有する光素子１０と、第１の主面２０ＳＡと第２の主面２０ＳＢとを有し、第２の主面２０ＳＢに光素子１０が配設されている配線板２０と、配線板２０の第１の主面２０ＳＡに下面３０ＳＢが固定されており下面３０ＳＢに対して垂直な光ファイバ貫通孔Ｈ３０がある保持部材３０と、光ファイバ貫通孔Ｈ３０に挿入されている光信号を伝送する光ファイバ５０と、を有し、配線板２０の第１の主面２０ＳＡに凹部Ｔ２０があり、保持部材３０は、凹部Ｔ２０の内部の接着剤４０を介して配線板２０に固定されている。
