To obtain an optical semiconductor module which is highly reliable, inexpensive and superior in mass-productivity by improving the service life and manufacturing workability of an optical semiconductor device and reducing variations in the optical characteristics to enhance manufacturing yield.

A recess 1a is formed in an optical semiconductor mounting member, and wiring paths 3 and 3' for supplying an optical semiconductor device 2 with power are formed in the recess 1a. Electrical connection is provided in the recess 1a, and the recess 1a is virtually filled with sealing resin for directly covering the optical semiconductor device 2. Thus, the range of choices of resin is extended, and the service life and process workability of the optical semiconductor device 2 are improved. Furthermore, optical tolerances are enhanced because of stable resin shape, thus improving the manufacturing yield.