A light source unit is disclosed for arranging on a plane and emitting a light beam oblique to the plane. The light source unit includes an illuminant element and a transparent encapsulator. The illuminant element has an upper surface and a lower surface both parallel to the plane. The transparent encapsulator physically contacts with the illuminant element and at least covers the upper surface of the illuminant element. The transparent encapsulator has an oblique surface above the upper surface and oblique to the upper surface. In addition, an optical inputting module having the light source unit mentioned above is disclosed.