A light emitting module including a light source set and a light guide member is provided. The light source set is suitable for providing a light and the light guide member is disposed above the light source set. The light guide member has a top surface, an opposite light incident surface, a first reflection surface, and an opposite light emergent surface connected between the top surface and the light incident surface. The top surface has a first concave surface serving a second reflection surface suitable for reflecting the light. Besides, a portion of the light reflected by the second reflection surface emerges from the light emergent surface through the reflection of the first reflection surface, and the other portion of the light directly emerges from the light emergent surface. Additionally, a surface light source device having the light emitting module is also provided.