An optical module 1A is an optical module, which is manufactured from an SOI substrate having a support substrate 10 and a semiconductor layer 14 disposed on a surface 10a of the support substrate 10 via an insulating layer 12, the optical module including a movable mirror 22 in which a mirror surface 22a is formed on a side face intersecting with a Y-direction, that is movable in the Y-direction, a photodiode 32 which is provided on the surface 10a of the support substrate 10, and is optically coupled to the mirror surface 22a of the movable mirror 22, a cap member 34 which is provided on the surface 10a of the support substrate 10, that airtight-seals the movable mirror 22 and the photodiode 32, and an element electrode part 36 which is provided through the support substrate 10 and the insulating layer 12, and is electrically connected to the photodiode 32. Thereby, it is possible to realize an optical module which is capable of enhancing the airtightness of an optical system including a movable mirror, and which also can be downsized.