It makes possible to inject a current into the current confinement region substantially uniformly. A surface emitting type optical semiconductor device includes a semiconductor active layer provided above a substrate; a first and second reflecting mirror layers sandwiching the semiconductor active layer to form an optical cavity in a direction perpendicular to the substrate; a plurality of current confinement regions provided in the second reflecting mirror layer so as to be separated by an impurity region having impurities; a semiconductor current diffusion layer provided on the second reflecting mirror layer so as to cover the current confinement regions; and an electrode portion which injects a current into the semiconductor active layer. The electrode portion comprising a first electrode provided on the semiconductor current diffusion layer so as to surround the current confinement regions and a second electrode provided on an opposite side of the substrate from the semiconductor active layer.