Provided is an optical module which has a connection to an optical fiber array and which can be densely mounted. To a board (101), two 30-mm-square package modules (102, 105) are mounted, and an optical waveguide of a 20-mm-square Si photonics lightwave circuit (103) mounted on the package module (102) and an optical fiber array (106) fixed to an optical fiber block (15*10 mm) (104) are connected. In addition, an emission end surface of the optical waveguide of the Si photonics lightwave circuit (103) is perpendicular to a mounting surface of the package module (102). In the present embodiment, the optical waveguide of the Si photonics lightwave circuit (103) is inclined at an appropriate angle, for example, 20 degrees, to a direction perpendicular to a right-side end surface. The optical fiber block (104) is fixed such that each of the optical fibers is also inclined at 20 degrees to a direction perpendicular to an end surface through which the optical fibers are connected to the Si photonics lightwave circuit (103).