An optical module on the invention provides a multi-layered ceramic package in which the LD, the sub-mount to mount the LD, the optical component to bend the optical axis of the light emitted from the LD toward the lens, and the monitor PD to monitor a portion of the light transmitted through the optical component. These components are mounted on a metal in the package with an adhesive. At least one of the sub-mount and the optical component provides a chamfer in a front bottom corner thereof to provide a room to receive fillets formed in the surfaces facing to and abutting against the other surface.