Disclosed is an optical module which improves optical coupling efficiency either when configured to receive an optical signal from an optical fiber with a light receiving element or when configured to receive an optical signal from a light emitting element with an optical fiber. The optical module includes: a substrate (1) having in the surface thereof a first groove (1a) and a second groove (1b) formed, with this second groove (1b) being configured to have a substantially V-shaped cross section formed deeper than the first groove and being formed in continuation from the first groove; and an internal waveguide (16) provided within the first groove (1a) of the substrate (1). The optical further modules a mirror portion (15) for changing an optical path, provided at the front end of the first groove (1a); an optical element (12a) mounted on the surface of the substrate (1) so as to face the mirror portion (15), and configured to emit an optical signal to a core (17) of the internal waveguide (16) via the mirror portion (15). Moreover, the optical module further includes an optical fiber (2) having a fiber cladding (22) placed within the second groove (1b) and a fiber core (21) optically connected to the core (17) of the internal waveguide (16).