An optical module where breaking of an optical fiber is avoided to improve ease of handling in the assembly process of the module and mechanical reliability of the module including resistance to impact. The optical module has a PD (3) and an optical fiber (5a) that are mounted on the same substrate (2). A covering section (6) for covering the optical fiber (5a) is placed on a deep trench section (24) having a predetermined depth in the Z2 direction from a V-groove-formed surface where a V-groove for mounting the optical fiber (5a) is formed. The distance h from an end face (3a) of the PD (3) to an end face (24a) of the deep trench section (24) and the distance k from an end face (51a) of the optical fiber (5a) to an end face (6a) of the covering section (6) satisfy the relationship of h>k. The optical fiber (5a) is mounted with both the end face (6a) of the covering section (6) and the end face (24a) of the deep trench section (24) made to be in contact with each other.