PROBLEM TO BE SOLVED: To provide a light source device for an endoscope, which is suitable for suppressing the deterioration of air circulation accompanying the increase of the number of fins.SOLUTION: The light source device for an endoscope includes: a light source unit having a light source lamp with heat sinks attached thereto a case body for storing the light source unit a first cooling fan arranged inside the case body and exhaust ports for exhausting the air, which is made to flow by the first cooling fan, to the external part of the case body. Each heat sink includes: an annular part tightly fixed to the light source lamp multiple fins which are arranged at prescribed pitch angle on the outer peripheral surface of the annular part and radially extended main holes axially penetrating the annular part and sub-holes having openings on the outer peripheral surface between the respective adjacent fins, while being connected to the main holes.
